Biology for Engineers PDF

i  BIOLOGY FOR ENGINEERS AUTHOR DR. ANNAMMA ODANETH (PHD) Associate Professor DBT‐ICT Centre for Energy Biosciences Institute of Chemical Technology Nathalal Parikh Marg Mat...

i  BIOLOGY FOR ENGINEERS AUTHOR DR. ANNAMMA ODANETH (PHD) Associate Professor DBT‐ICT Centre for Energy Biosciences Institute of Chemical Technology Nathalal Parikh Marg Matunga, Maharashtra (India) REVIEWER DR. N. RAVI SUNDARESAN Associate Professor Department of Microbiology and Cell Biology Indian Institute of Science, Bengaluru Bengaluru, Karnataka (India) All India Council for Technical Education Nelson Mandela Marg, Vasant Kunj, New Delhi, 110070 ii BOOK AUTHOR DETAILS Dr. Annamma Odaneth, Ph.D, Associate Professor, DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Nathalal Parikh Marg, Matunga, Maharashtra (India) Email ID: [email protected] BOOK REVIEWER DETAILS Dr. N. Ravi Sundaresan, Associate Professor, Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, Karnataka (India) Email ID: [email protected] BOOK COORDINATOR (S) – English Version 1. Dr. Ramesh Unnikrishnan, Advisor-II, Training and Learning Bureau, All India Council for Technical Education (AICTE), New Delhi, India Email ID: advtlb@aicte‐india.org Phone Number: 011-29581215 2. Dr. Sunil Luthra, Director, Training and Learning Bureau, All India Council for Technical Education (AICTE), New Delhi, India Email ID: directortlb@aicte‐india.org Phone Number: 011-29581210 3. Mr. Sanjoy Das, Assistant Director, Training and Learning Bureau, All India Council for Technical Education (AICTE), New Delhi, India Email ID: ad1tlb@aicte‐india.org Phone Number: 011-29581339 July, 2023 © All India Council for Technical Education (AICTE) ISBN : 978-81-963773-0-4 All rights reserved. No part of this work may be reproduced in any form, by mimeograph or any other means, without permission in writing from the All India Council for Technical Education (AICTE). Further information about All India Council for Technical Education (AICTE) courses may be obtained from the Council Office at Nelson Mandela Marg, Vasant Kunj, New Delhi-110070. Printed and published by All India Council for Technical Education (AICTE), New Delhi. Attribution-Non Commercial-Share Alike 4.0 International (CC BY-NC-SA 4.0) Disclaimer: The website links provided by the author in this book are placed for informational, educational & reference purpose only. The Publisher do not endorse these website links or the views of the speaker / content of the said weblinks. In case of any dispute, all legal matters to be settled under Delhi Jurisdiction, only. iii iv  ACKNOWLEDGEMENT The authors are grateful to the authorities of AICTE, particularly Prof. T.G. Sitharam, Chairman; Dr. Abhay Jere, Vice-Chairman; Prof. Rajiv Kumar, Member-Secretary, Dr. Ramesh Unnikrishnan, Advisor-II and Dr. Sunil Luthra, Director, Training and Learning Bureau for their planning to publish the books on Biology for Engineers. We sincerely acknowledge the valuable contributions of the reviewer of the book N. RAVI SUNDARESAN, Associate Professor, Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru for making it students’ friendly and giving a better shape in an artistic manner. This book is an outcome of many rounds of discussions, delibrations, contributions and suggestions of all members of my group at the Institute of Chemical Technology. We have attempted to incorporate all aspects of basic biology. The suggestions of AICTE members, experts and authors who shared their opinion and thought to further develop the engineering education in our country. It is also with great honour that I state that this book is aligned to the AICTE Model Curriculum and in line with the guidelines of National Education Policy (NEP) -2020. Towards promoting education in regional languages, this book is being translated in scheduled Indian regional languages. Acknowledgements are due to the contributors and different workers in this field whose published books, review articles, papers, photographs, footnotes, references and other valuable information enriched us at the time of writing the book. Author v  PREFACE "Biology for Engineers" is the result of our extensive experience teaching basic biology courses. As a bioprocess technology professor, I've always been fascinated by the intersection of biology and technology. There is an unmet the need for a comprehensive guide to biology that is understandable to non-scientists. Biology is a complicated and intimidating subject, but it is also a fascinating subject that has an impact on our daily lives. Engineers, in particular, must understand the fundamentals of biology as they intend to work on biotechnology, medical devices, and environmental sustainability projects. My guide would present topics such as genetics, cellular biology, ecology, and evolution in an engaging and easy-to-follow manner. To help readers relate to the material, I have used real-world examples and analogies. I would also include interactive elements such as quizzes and simulations to improve learning. We can foster a greater appreciation for the natural world and inspire innovation in fields ranging from medicine to renewable energy by making biology accessible to everyone. We have included the topics recommended by AICTE in a very systematic and orderly manner throughout the book, keeping in mind the purpose of broad coverage as well as providing essential supplementary information. Attempts have been made to explain the subject's fundamental concepts as simply as possible. During the manuscript preparation process, we considered various standard text books and developed sections such as critical questions, solved and supplementary problems, and so on. By bridging the gap between biology and engineering, I hope to inspire more innovation in this field and encourage interdisciplinary collaboration. The topics are presented in a constructive manner, so that an Engineering degree prepares students to work in various sectors or in national laboratories at the cutting edge of technology. Whether you are an experienced engineer or simply interested in the potential of biotechnology, this book will provide you with valuable insights into this exciting field. If you are an engineer looking to expand your knowledge or are simply interested in the future of biotechnology, this book is for you. We appreciate your interest in providing us with all beneficial comments and suggestions that will contribute to the improvement of the future editions of the book. Your feedback is essential in helping us make necessary changes and updates to ensure that our content remains relevant and up-to-date. We take pride in placing this book in the hands of teachers vi and students, knowing that it will serve as a valuable resource for their learning and growth. It was indeed a big pleasure to work on different aspects covered in the book, from research to writing, editing, and design. We hope that our efforts will translate into a positive impact on your educational journey. As we continue to evolve and improve our content, we welcome your ongoing support and feedback. Together, we can create a better learning experience for all. Author vii  OUTCOME BASED EDUCATION For the implementation of an outcome based education the first requirement is to develop an outcome based curriculum and incorporate an outcome based assessment in the education system. By going through outcome based assessments evaluators will be able to evaluate whether the students have achieved the outlined standard, specific and measurable outcomes. With the proper incorporation of outcome based education there will be a definite commitment to achieve a minimum standard for all learners without giving up at any level. At the end of the programme running with the aid of outcome based education, a student will be able to arrive at the following outcomes: PO1. Engineering knowledge: Apply the knowledge of mathematics, science, engineering fundamentals, and an engineering specialization to the solution of complex engineering problems. PO2. Problem analysis: Identify, formulate, review research literature, and analyze complex engineering problems reaching substantiated conclusions using first principles of mathematics, natural sciences, and engineering sciences. PO3. Design / development of solutions: Design solutions for complex engineering problems and design system components or processes that meet the specified needs with appropriate consideration for the public health and safety, and the cultural, societal, and environmental considerations. PO4. Conduct investigations of complex problems: Use research-based knowledge and research methods including design of experiments, analysis and interpretation of data, and synthesis of the information to provide valid conclusions. PO5. Modern tool usage: Create, select, and apply appropriate techniques, resources, and modern engineering and IT tools including prediction and modeling to complex engineering activities with an understanding of the limitations. PO6. The engineer and society: Apply reasoning informed by the contextual knowledge to assess societal, health, safety, legal and cultural issues and the consequent responsibilities relevant to the professional engineering practice. PO7. Environment and sustainability: Understand the impact of the professional engineering solutions in societal and environmental contexts, and demonstrate the knowledge of, and need for sustainable development. PO8. Ethics: Apply ethical principles and commit to professional ethics and responsibilities and norms of the engineering practice. PO9. Individual and team work: Function effectively as an individual, and as a member or leader in diverse teams, and in multidisciplinary settings. viii PO10. Communication: Communicate effectively on complex engineering activities with the engineering community and with society at large, such as, being able to comprehend and write effective reports and design documentation, make effective presentations, and give and receive clear instructions. PO11. Project management and finance: Demonstrate knowledge and understanding of the engineering and management principles and apply these to one’s own work, as a member and leader in a team, to manage projects and in multidisciplinary environments. PO12. Life-long learning: Recognize the need for, and have the preparation and ability to engage in independent and life-long learning in the broadest context of technological change. ix  COURSE OUTCOMES After completion of the course the students will be able to: CO 1: Describe how biological observations of 18th Century that lead to major discoveries. CO 2: Convey that classification per se is not what biology is all about but highlight the underlying criteria, such as morphological, biochemical and ecological CO 3: Highlight the concepts of recessiveness and dominance during the passage of genetic material from parent to offspring CO 4: Convey that all forms of life have the same building blocks and yet the manifestations are as diverse as one can imagine CO 5: Classify enzymes and distinguish between different mechanisms of enzyme action. CO 6: Identify DNA as a genetic material in the molecular basis of information transfer. CO 7: Analyse biological processes at the reductionistic level CO 8: Apply thermodynamic principles to biological systems CO 9: Identify and classify microorganisms. Expected Mapping with Programme Outcomes Course (1- Weak Correlation; 2- Medium correlation; 3- Strong Correlation) Outcomes PO-1 PO-2 PO-3 PO-4 PO-5 PO-6 PO-7 PO-8 PO-9 PO-10 PO-11 PO-12 CO‐1 1 2 2 2 1 - 2 - - - 1 2 CO‐2 1 1 2 1 - - 3 - - - - - CO‐3 1 3 2 1 - - 2 - - - - - CO‐4 1 3 3 2 1 - 2 - - - - - CO‐5 1 3 2 1 1 - 2 - - - - - CO‐6 1 3 3 2 1 - 2 - - - - - CO‐7 1 3 3 2 1 - 2 - - - - - CO‐8 1 2 3 1 - - 2 - - - - - CO‐9 1 3 2 1 - - 2 - - - - - x  GUIDELINES FOR TEACHERS To implement Outcome Based Education (OBE) knowledge level and skill set of the students should be enhanced. Teachers should take a major responsibility for the proper implementation of OBE. Some of the responsibilities (not limited to) for the teachers in OBE system may be as follows:  Within reasonable constraint, they should manoeuvre time to the best advantage of all students.  They should assess the students only upon certain defined criterion without considering any other potential ineligibility to discriminate them.  They should try to grow the learning abilities of the students to a certain level before they leave the institute.  They should try to ensure that all the students are equipped with the quality knowledge as well as competence after they finish their education.  They should always encourage the students to develop their ultimate performance capabilities.  They should facilitate and encourage group work and team work to consolidate newer approach.  They should follow Blooms taxonomy in every part of the assessment. Bloom’s Taxonomy Teacher should Student should be Possible Mode of Level Check able to Assessment Students ability to Create Design or Create Mini project create Students ability to Evaluate Argue or Defend Assignment justify Students ability to Differentiate or Project/Lab Analyse distinguish Distinguish Methodology Students ability to Operate or Technical Presentation/ Apply use information Demonstrate Demonstration Students ability to Understand Explain or Classify Presentation/Seminar explain the ideas Students ability to Remember Define or Recall Quiz recall (or remember) xi  GUIDELINES FOR STUDENTS Students should take equal responsibility for implementing the OBE. Some of the responsibilities (not limited to) for the students in OBE system are as follows:  Students should be well aware of each UO before the start of a unit in each and every course.  Students should be well aware of each CO before the start of the course.  Students should be well aware of each PO before the start of the programme.  Students should think critically and reasonably with proper reflection and action.  Learning of the students should be connected and integrated with practical and real life consequences.  Students should be well aware of their competency at every level of OBE. xii  LIST OF ABBREVIATIONS General Terms Abbreviations Full form Abbreviations Full form DNA Deoxyribonucleic acid Severe Acute Respiratory SARS-CoV-2 RNA Ribonucleic acid Syndrome Corona Virus 2 H AEC2 Angiotensin-converting enzyme 2 Hydrogen group OH AMP Adenosine monophosphate Hydroxyl group A Adenine ADP Adenosine diphosphate T ATP Adenosine triphosphate Thymine G C Carbon Guanine C O Oxygen Cytosine Pyl CO2 Carbon dioxide Pyrrolysine Se NH3 Ammonia Selenocysteine Nicotinamide adenine Cys Cysteine NADH dinucleotide R Rectus Nicotinamide adenine NADPH S Sinister dinucleotide phosphate D Dextrorotatory FAD/FADH2 Flavin adenine dinucleotide L Levorotatory 3-PGA 3-phosphoglyceric acid U Uracil TCA Tricarboxylic acid mRNA Messenger RNA GDP Guanosine diphosphate rRNA Ribosomal RNA GTP Guanosine triphosphate tRNA Transfer RNA C6H12O6 Glucose VDL Very low-density lipoprotein H2 S Hydrogen sulfide IDL Intermediate-density lipoprotein H2O Water LDL Low-density lipoprotein O2 Oxygen HDL High-density lipoprotein CoA Co- enzyme A SEC Size Exclusion Chromatography RuBP Ribulose-1, 5-bisphosphate SDS Sodium dodecyl sulfate Pi Inorganic phosphate Polyacrylamide gel G3P Glyceraldehyde 3-phosphate PAGE electrophoresis EC Energy Charge pI Isoelectric point DAP Dihydroxyacetone phosphate BCA Bicinchoninic Acid GAP Glyceraldehyde 3-phosphate HSP Heat shock protein Cfu Colony forming unit xiii  LIST OF SYMBOLS Symbols Description Symbols Description ΔG Free energy change e- Electron ΔG° Standard Free-Energy Change H+ Proton K equilibrium constant xiv  LIST OF FIGURES Unit 1 Introduction Fig 1. 1 Level of organization 4 Fig 1. 2 Eye and the camera – Similarities and differences in structure and function 6 Fig 1. 3 Timeline for important discoveries in biology 6 Fig 1. 4 Information table 9 Fig 1. 5 Representation of the Brownian motion 10 Unit 2 Classification Fig. 2. 1 Classification system 17 Fig. 2. 2 Structure of Unicellular and Multicellular organisms 19 Fig. 2. 3 Ultrastructure of a) Prokaryote and b) Eukaryote 20 Fig. 2. 4 Habitat in different systems 24 Fig. 2. 5 Structure of Escherichia coli 26 Fig. 2. 6 Structure of Saccharomyces cerevisiae 27 Fig. 2. 7 Structure of Drosophila melanogaster 28 Fig. 2. 8 Structure of C.elegans 28 Fig. 2. 9 Structure of Arabidopsis thaliana 29 Fig. 2. 10 Mus musculus 29 Fig. 2. 11 Semnopithecus entellus 30 Unit 3 Genetics Fig. 3. 1 Gregor Johann Mendel ‘Father of Genetics’ 37 Fig. 3. 2 Contrasting Traits Studied by Mendel in Pea plant 38 Fig. 3. 3 Law of Dominance 40 Fig. 3. 4 Law of Independent Assortment 41 Fig. 3. 5 Segregation of height character in pea plant 43 Fig. 3. 6 Example of Epistasis in Bee 45 Fig. 3. 7 The progressive and regressive phases of cell division 47 Fig. 3. 8 Different phases involved in Meiosis 48 Fig. 3. 9 (a) Deletion (b) Duplication (c) Inversion (e) Translocation ( 52 Fig. 3. 10 : Complementation Test: An illustration of a complementation test 55 Unit 4 Biomolecules Fig. 4. 1 Biomolecules 64 Fig. 4. 2 Condensation reaction 65 Fig. 4. 3 Hydrolysis reaction 77 Fig. 4. 4 Empirical structure of amino acids 66 Fig. 4. 5 Amino acids classified on the basis of polarity 67 Fig. 4. 6 Stereochemistry of Amino acids 68 Fig. 4. 7 Formation of the Peptide Bond 69 Fig. 4. 8 Disulfide Bonds 70 Fig. 4. 9 Primary protein structure 70 Fig. 4. 10 Monosaccharides 72 Fig. 4. 11 Stereochemistry of glucose 72 Fig. 4. 12 : α-glycosidic linkage in maltose 73 Fig. 4. 14 α-glycosidic linkage in Maltose 73 Fig. 4. 15 β-glycosidic linkage in Maltose 74 Fig. 4. 16 1,6-glycosidic bond in amylopectin 74 xv Fig. 4. 17 Difference in the arrangement of glucose monomers in different polysaccharides 75 Fig. 4. 18 Plant Cellulose 76 Fig. 4. 20 Starch in plants 77 Fig. 4. 21 Structure of Starch 77 Fig. 4. 22 Nucleic acids 78 Fig. 4. 23 Difference in sugars present in DNA & RNA 79 Fig. 4. 24 Transfer RNA (tRNA) 80 Fig. 4. 25 Phosphodiester bond in a strand of a polynucleotide 81 Fig. 4. 26 Hydrogen bonding in base pairs 82 Fig. 4. 27 DNA packaging in eukaryote 82 Fig. 4. 28 Formation of Triglyceride 83 Fig. 4. 29 Arrangements of Lipid 85 Fig. 4. 30 Structure of Lipoproteins 86 Unit 5 Enzymes Fig. 5. 1 Schematic diagram of lock and key model 98 Fig. 5. 2 Schematic Diagram of Induced fit model 98 Fig. 5. 3 Enzymatic reaction with respect to Substrate consumption and time 99 Fig. 5. 4 Difference between Vmax and Km 100 Fig. 5. 5 Mechanism of Competitive inhibition 103 Fig. 5. 6 Effect of Competitive inhibition on Enzyme activity 104 Fig. 5. 7 Mechanism of Non-Competitive inhibition 104 Fig. 5. 8 Effect of Non-Competitive inhibition on Enzyme activity 105 Fig. 5. 9 Mechanism of Uncompetitive inhibition 105 Fig. 5. 10 Effect of Uncompetitive inhibition on Enzyme activity 106 Fig. 5. 11 Effect of allosteric enzyme on the graph 107 Unit 6 Information transfer Fig. 6. 1 Griffith experiment on mice 114 Fig. 6. 2 Hershey-Chase experiment 115 Fig. 6. 3 X-ray diffraction photo of dsDNA obtained by Rosalind Franklin 116 Fig. 6. 4 Double helical structure of DNA with base pairing 117 Fig. 6. 5 Structure of A, B, and Z forms of DNA 119 Fig. 6. 6 Gene structure 120 Fig. 6. 7 Hierarchies of Genome Organization 121 Fig. 6. 8 Human Karyotype. 122 Fig. 6. 9 Central Dogma of life 123 Fig. 6. 10 DNA replication 125 Fig. 6. 11 Process of Transcription 126 Fig. 6. 12 Prokaryotic promoter 126 Fig. 6. 13 Eukaryotic RNA pol II promoter 127 Fig. 6. 14 Structure of tRNA 129 Fig. 6. 15 Structure of the ribosome with its binding sites 129 Fig. 6. 16 The genetic code dictionary 131 Fig. 6. 17 Protein synthesis on ribosomes 132 Fig. 6. 18 Structure of lac operon 133 Fig. 6. 19 Regulation of Lac operon 134 Fig. 6. 20 Holliday junction formation, Double crossover 136 Unit 7 Macromolecular analysis. Fig. 7. 1 Anion exchange chromatography 146 Fig. 7. 2 Size Exclusion Chromatography 147 xvi Fig. 7. 3 Affinity chromatography 147 Fig. 7. 4 Primary protein structure 152 Fig. 7. 5 Intramolecular Hydrogen bonding in amino acid chain 153 Fig. 7. 6 Parallel β-pleated sheet 153 Fig. 7. 8 Tertiary structure of protein 154 Fig. 7. 9 Protein packaging in eukaryotes 155 Fig. 7. 10 Transport Proteins: Channel & Carrier Proteins 157 Fig. 7. 11 AEC2, a receptor protein to which spike protein of SARS-CoV-2 binds 158 Fig. 7. 12 Collagen as structural protein of skin 160 Unit 8 Metabolism Fig. 8. 1 Interconversion of ATP and ADP occurs in a cycle 173 Fig. 8. 2 Energy release from ATP 174 Fig. 8. 3 Flow of energy in metabolism 175 Fig. 8. 4 Catabolic and anabolic pathways and their energy relationship 176 Fig. 8. 5 Overall cellular respiration 177 Fig. 8. 6 Reactions in Glycolysis 179 Fig. 8. 7 Connecting link between glycolysis and Krebs cycle 181 Fig. 8. 8 Reactions in Krebs cycle 182 Fig. 8. 9 Electron transport chain 184 Fig. 8. 10 Overview of photosynthesis 185 Fig. 8. 11 Relationship between photosynthesis and cellular respiration 187 Unit 9 Microbiology Fig. 9. 1 Gram-positive (purple) and Gram-negative (pink) 201 Fig. 9. 2 Compound Microscope 202 Fig. 9. 3 Electron microscope 221 Fig. 9. 4 Streak Plate Technique 205 Fig. 9. 5 Spread Plate Technique 206 Fig. 9. 6 Pour Plate Technique 207 Fig. 9. 7 Autoclave 208 Fig. 9. 8 Laminar Air Flow Source 209 Fig. 9. 9 Bacterial growth in liquid, solid and semi-solid media 210 Fig. 9. 10 Bacterial growth on agar plates 211 Fig. 9. 11 Growth Curve 212 xvii  LIST OF TABLES Unit 2 Classification Table 2. 1 17 Unit 4 Biomolecules Table 4. 1 Classification of carbohydrates 75 Unit 5 Enzymes Table 5. 1 Classification of enzymes 95 Table 5. 2 Function of co enzyme and their precursors 96 Table 5. 3 Examples for metal ions as a cofactors 97 Unit 6 Information transfer Table 6. 1 Forms of DNA 118 Table 6. 2 Chromosomes number in different organisms 122 Table 6. 3 Catabolite repression 135 Unit 7 Macromolecular analysis Table 7. 1 Assays used for protein estimation 149 Unit 8 Metabolism Table 8. 1 Difference between endergonic and exergonic reactions 168 Table 8. 2 Standard free energies for different types of reactions 170 Table 8. 3 Activated Carriers with their high-energy chemical groups 172 Table 8. 4 Differences in photosynthesis and cellular respiration 187 Unit 9 Microbiology Table 9. 1 Difference between Light and Electron Microscope 202 xviii  CONTENTS Foreword iv Acknowledgement v Preface vi Outcome Based Education viii Course Outcomes x Guidelines for Teachers xi Guidelines for Students xii List of Abbreviations xiii Abbreviations and Symbols xiv List of Figures xv List of Tables xviii UNIT 1 INTRODUCTION UNIT SPECIFICS......................................................................................................................................................... 1 RATIONALE................................................................................................................................................................ 2 PRE-REQUISITES........................................................................................................................................................ 2 UNIT OUTCOMES....................................................................................................................................................... 2 1.1 INTRODUCTION TO BIOLOGY.......................................................................................................................... 3 1.1.1 The complexity of biological systems.............................................................................................................. 3 1.1.2 Biology looks for a mechanism........................................................................................................................ 3 1.1.3 Biology is multi-scaled.................................................................................................................................... 4 1.1.4 Biology is integrative....................................................................................................................................... 4 1.2 FUNDAMENTAL SIMILARITIES AND DIFFERENCES................................................................................... 5 1.3 ASPECT OF BIOLOGY AS AN INDEPENDENT SCIENTIFIC DISCIPLINE.................................................... 6 1.4 PHILOSOPHY OF BIOLOGY................................................................................................................................ 7 1.5 HISTORY OF BIOLOGY....................................................................................................................................... 7 1.6 NEED TO STUDY BIOLOGY............................................................................................................................... 8 1.7 OBSERVATIONS THAT LEAD TO IMPORTANT DISCOVERIES IN BIOLOGY........................................... 9 UNIT SUMMARY.......................................................................................................................................................10 EXERCISES.................................................................................................................................................................11 KNOW MORE.............................................................................................................................................................12 REFERENCES AND SUGGESTED READINGS.......................................................................................................12 xix  UNIT 2 CLASSIFICATION. UNIT SPECIFICS........................................................................................................................................................13 RATIONALE...............................................................................................................................................................14 PRE-REQUISITES.......................................................................................................................................................14 UNIT OUTCOMES......................................................................................................................................................14 2.1 INTRODUCTION..................................................................................................................................................15 2.2 HIERARCHY OF LIFE FORMS...........................................................................................................................15 2.2.1Traditional classification..................................................................................................................................15 2.2.2 Biological classification..................................................................................................................................16 2.2.3 Five kingdom classification system................................................................................................................16 2.3 CLASSIFICATION................................................................................................................................................18 2.3.1 Cellularity.......................................................................................................................................................18 2.3.2 Ultrastructure of prokaryotes or eukaryotes....................................................................................................19 2.3.3 Energy and carbon utilization.........................................................................................................................20 2.3.4 Excretion.........................................................................................................................................................21 2.3.5 Habitat.............................................................................................................................................................22 2.3.6 Molecular taxonomy.......................................................................................................................................25 2.4 MODEL ORGANISMS..........................................................................................................................................26 UNIT SUMMARY.......................................................................................................................................................30 EXERCISES.................................................................................................................................................................30 KNOW MORE.............................................................................................................................................................32 REFERENCES AND SUGGESTED READINGS.......................................................................................................32 UNIT 3 GENETICS. UNIT SPECIFICS........................................................................................................................................................34 RATIONALE...............................................................................................................................................................35 PRE-REQUISITES.......................................................................................................................................................35 UNIT OUTCOMES......................................................................................................................................................35 3.1INTRODUCTION TO GENETICS.........................................................................................................................36 3.1.1 Past, modern and future genetics.....................................................................................................................36 3.1.2 Heredity and principles of heredity.................................................................................................................37 3.2 MENDEL’S LAWS OF INHERITANCE..............................................................................................................38 3.3 LAWS OF INHERITANCE PROPOSED BY MENDEL:.....................................................................................39 xx  3.3.1 Law of Dominance..........................................................................................................................................39 3.3.2 Law of Independent Assortment.....................................................................................................................41 3.3.3 Law of Segregation..........................................................................................................................................41 3.4 CONCEPT OF ALLELE........................................................................................................................................43 3.5 GENE MAPPING...................................................................................................................................................44 3.6 GENE INTERACTION..........................................................................................................................................45 3.6.1 Epistasis..........................................................................................................................................................45 3.6.2 Types of Epistasis...........................................................................................................................................46 3.7 MITOSIS AND MEOSIS.......................................................................................................................................46 3.7.1 Gene Transmission in Mitosis.........................................................................................................................46 3.7.2 Gene Transmission in Meiosis........................................................................................................................48 3.8 CONCEPT OF MAPPING PHENOTYPE TO GENOTYPE.................................................................................49 3.9 CHROMOSOMAL ABNORMALITIES AND SYNDROMES.............................................................................50 3.9.1 Single gene disorders in humans.....................................................................................................................50 3.9.2 Structural chromosomal abnormalities............................................................................................................51 3.9.3 Monogenic Disorders......................................................................................................................................52 3.10 CONCEPT OF COMPLEMENTATION USING GENETICS............................................................................54 UNIT SUMMARY.......................................................................................................................................................56 EXERCISES.................................................................................................................................................................57 KNOW MORE.............................................................................................................................................................60 REFERENCES AND SUGGESTED READINGS.......................................................................................................61 UNIT 4 BIOMOLECULES. UNIT SPECIFICS........................................................................................................................................................62 RATIONALE...............................................................................................................................................................63 PRE-REQUISITES.......................................................................................................................................................63 UNIT OUTCOMES......................................................................................................................................................63 4.1 INTRODUCTION..................................................................................................................................................64 4.2 STRUCTURAL ORGANIZATION OF COMPLEX BIOMOLECULES..............................................................65 4.2.1 Monomers & Polymers...................................................................................................................................65 4.3 PROTEINS.............................................................................................................................................................66 4.3.1 Amino acids:...................................................................................................................................................66 4.3.2 Peptide Bond Formation and Primary Protein Structure:................................................................................68 4.3.3 Protein Shape and Function............................................................................................................................70 4.4 CARBOHYDRATES.............................................................................................................................................71 4.4.1 Monosaccharides.............................................................................................................................................71 xxi  4.4.2 Oligosaccharides.............................................................................................................................................73 4.4.3 Types of linkages............................................................................................................................................73 4.5 NUCLEIC ACIDS..................................................................................................................................................77 4.5.1 DNA................................................................................................................................................................78 4.5.2 RNA................................................................................................................................................................79 4.5.3 Linkages in DNA & RNA...............................................................................................................................80 4.5.4 DNA packaging..............................................................................................................................................82 4.6 LIPIDS....................................................................................................................................................................83 4.6.1 Classification of Lipids:..................................................................................................................................83 4.6.2 Lipoproteins....................................................................................................................................................85 UNIT SUMMARY.......................................................................................................................................................86 EXERCISES.................................................................................................................................................................87 REFERENCES AND SUGGESTED READINGS.......................................................................................................92 UNIT 5 ENZYMES. UNIT SPECIFICS........................................................................................................................................................93 RATIONALE...............................................................................................................................................................94 PRE-REQUISITES.......................................................................................................................................................94 UNIT OUTCOMES......................................................................................................................................................94 5.1 INTRODUCTION..................................................................................................................................................95 5.2 ENZYME CLASSIFICATION...............................................................................................................................95 5.3 ISOZYMES............................................................................................................................................................96 5.4 ENZYME ASSOCIATED METAL IONS AND COFACTORS...........................................................................96 5.5 MECHANISM OF ACTION OF ENZYMES........................................................................................................97 5.5.1 Lock-And-Key Theory....................................................................................................................................98 5.8 MECHANISM OF ENZYME ACTION.................................................................................................................99 5.9 KINETICS OF ENZYME-CATALYSED REACTION.......................................................................................100 5.10 LYSOZYME.......................................................................................................................................................101 5.11.1 Structure of lysozyme.................................................................................................................................101 5.11.2 Applications:...............................................................................................................................................102 5.12 CHYMOTRYPSIN.............................................................................................................................................102 5.13 ENZYME INHIBITION.....................................................................................................................................102 5.13.1 Competitive inhibition................................................................................................................................102 5.13.2 Non-Competitive inhibition........................................................................................................................104 5.13.3 Uncompetitive inhibition............................................................................................................................105 xxii 5.14 ALLOSTERIC ENZYMES................................................................................................................................106 5.15 RNA CATALYSIS.............................................................................................................................................107 5.15.1Applications.................................................................................................................................................107 UNIT SUMMARY.....................................................................................................................................................108 EXERCISES...............................................................................................................................................................108 KNOW MORE...........................................................................................................................................................110 REFERENCES AND SUGGESTED READINGS.....................................................................................................110 UNIT 6 INFORMATION TRANSFER UNIT SPECIFICS......................................................................................................................................................111 RATIONALE.............................................................................................................................................................112 PRE-REQUISITES.....................................................................................................................................................112 UNIT OUTCOMES....................................................................................................................................................112 6.1 INTRODUCTION................................................................................................................................................113 6.1.1 DNA as a Genetic Material...........................................................................................................................113 6.1.2 Transforming principle: Griffith’s Experiment.............................................................................................113 6.1.3 Hershey-Chase Experiment...........................................................................................................................114 6.2 DOUBLE HELICAL STRUCTURE OF DNA.....................................................................................................115 6.3 HIERARCHY OF DNA.......................................................................................................................................121 6.4 MOLECULAR BASIS OF INFORMATION TRANSFER.................................................................................123 6.5 DNA REPLICATION...........................................................................................................................................123 6.6 PROTEIN SYNTHESIS.......................................................................................................................................125 6.6.1 Transcription.................................................................................................................................................125 6.6.2 Translation....................................................................................................................................................128 6.7 GENE EXPRESSION AND REGULATION.......................................................................................................132 6.7.1 Lac Operon Model........................................................................................................................................133 6.8 DNA RECOMBINATION...................................................................................................................................135 UNIT SUMMARY.....................................................................................................................................................136 EXERCISES...............................................................................................................................................................137 KNOW MORE...........................................................................................................................................................142 REFERENCES AND SUGGESTED READINGS.....................................................................................................143 UNIT 7 MACROMOLECULAR ANALYSIS. UNIT SPECIFICS......................................................................................................................................................144 RATIONALE.............................................................................................................................................................145 xxiii PRE-REQUISITES.....................................................................................................................................................145 UNIT OUTCOMES....................................................................................................................................................145 7.1 REDUCTIONIST APPROACH...........................................................................................................................146 7.2 ANALYSIS OF PROTEINS.................................................................................................................................146 7.2.1 Chromatographic techniques.........................................................................................................................146 7.2.2 Electrophoretic techniques............................................................................................................................148 7.2.3 Protein Assays...............................................................................................................................................149 7.3 PROPERTIES OF PROTEINS.............................................................................................................................149 7.4 STRUCTURE OF PROTEINS.............................................................................................................................151 7.4.1 Forces that stabilize protein structures..........................................................................................................151 7.4.2 Primary Structure:.........................................................................................................................................152 7.4.3 Secondary structure.......................................................................................................................................152 7.4.4 Tertiary Structure..........................................................................................................................................154 7.4.5 Quaternary Structure.....................................................................................................................................154 7.5 FUNCTIONS OF PROTEINS..............................................................................................................................155 7.5.1 Transport Proteins.........................................................................................................................................156 7.5.2 Receptor Proteins..........................................................................................................................................157 7.5.3 Hormonal Proteins:.......................................................................................................................................158 7.5.4 Enzymes........................................................................................................................................................159 7.5.5 Structural Proteins.........................................................................................................................................159 UNIT SUMMARY.....................................................................................................................................................160 EXERCISES...............................................................................................................................................................160 REFERENCES AND SUGGESTED READINGS.....................................................................................................164 UNIT 8 METABOLISM UNIT SPECIFICS......................................................................................................................................................165 RATIONALE.............................................................................................................................................................166 PRE-REQUISITES.....................................................................................................................................................166 UNIT OUTCOMES....................................................................................................................................................166 8.1 INTRODUCTION................................................................................................................................................167 8.2 THERMODYNAMICS: APPLIED TO BIOLOGICAL SYSTEMS....................................................................167 8.1.1 Bioenergy and biological reactions...............................................................................................................168 8.1.2 Free-Energy Change, ΔG..............................................................................................................................168 8.1.3 Activated Carriers of Electrons.....................................................................................................................171 8.1.4 Concept of Energy charge.............................................................................................................................173 xxiv  8.1.5 Oxidation and Reduction Reactions..............................................................................................................174 8.3 METABOLIC PATHWAYS................................................................................................................................175 8.3.1 The process of cellular respiration................................................................................................................177 8.3.2 Glycolysis.....................................................................................................................................................177 8.3.3 Krebs cycle/Citric acid cycle........................................................................................................................181 8.3.4 Electron transport chain................................................................................................................................183 8.3.5 Photosynthesis..............................................................................................................................................185 8.3.6 Difference between cellular respiration and photosynthesis.........................................................................187 UNIT SUMMARY.....................................................................................................................................................188 EXERCISES...............................................................................................................................................................188 KNOW MORE...........................................................................................................................................................191 REFERENCES AND SUGGESTED READINGS.....................................................................................................192 UNIT 9 MICROBIOLOGY UNIT SPECIFICS......................................................................................................................................................194 RATIONALE.............................................................................................................................................................195 PRE-REQUISITES.....................................................................................................................................................195 UNIT OUTCOMES....................................................................................................................................................195 9.1 INTRODUCTION................................................................................................................................................196 9.2 CONCEPT OF SINGLE-CELL ORGANISMS....................................................................................................196 9.2.1 Characteristics of Unicellular Organisms......................................................................................................197 9.2.2 Characteristics of Multicellular Organisms...................................................................................................197 9.3 CONCEPT OF SPECIES AND STRAIN.............................................................................................................198 9.3.1 Species..........................................................................................................................................................198 9.3.2 Strain.............................................................................................................................................................198 9.4 IDENTIFICATION AND CLASSIFICATION OF MICROORGANISMS.........................................................199 9.4.1 Identification of Microorganisms..................................................................................................................201 9.5 MICROSCOPY....................................................................................................................................................201 9.6 ECOLOGICAL ASPECTS OF SINGLE-CELLED ORGANISMS.....................................................................203 9.6.1 Role of microorganisms in the ecosystem.....................................................................................................204 9.7 CULTURING OF MICROORGANISMS IN THE LAB.....................................................................................204 9.7.1 Inoculation....................................................................................................................................................204 9.7.2 Isolation........................................................................................................................................................205 9.7.3 Spread plate method......................................................................................................................................205 9.7.4 Pour plate method.........................................................................................................................................206 9.8 STERILIZATION AND MEDIA COMPOSITIONS...........................................................................................207 xxv  9.8.1 Sterilization...................................................................................................................................................207 9.8.2 Types of media..............................................................................................................................................210 9.9 GROWTH KINETICS..........................................................................................................................................212 9.9.1 Mathematics of Growth Kinetics:.................................................................................................................213 9.10 DIFFERENT FIELDS OF MICROBIOLOGY...................................................................................................214 9.11 APPLICATIONS OF MICROBIOLOGY..........................................................................................................215 UNIT SUMMARY.....................................................................................................................................................216 EXERCISES...............................................................................................................................................................216 PRACTICAL..............................................................................................................................................................218 REFERENCES AND SUGGESTED READINGS.....................................................................................................218 CO AND PO ATTAINMENT TABLE...................................................................................................................220 INDEX.......................................................................................................................................................................226 xxvi  Biology for Engineers | 1 1 Introduction UNIT SPECIFICS Through this unit we have discussed the following aspects: Basic of biology The fundamental differences between science and engineering. The aspect of biology as an independent scientific discipline Why do we need to study biology? Biological observations of the 18th Century lead to major discoveries. Brownian motion and the origin of thermodynamics by referring to the original observation of Robert Brown and Julius Mayor. Discoveries made in biology till today. How engineering is involved in biology The practical applications of the topics are discussed for generating further curiosity and creativity as well as improving problem solving capacity. Besides giving a large number of multiple choice questions as well as questions of short and long answer types marked in two categories following lower and higher order of Bloom’s taxonomy, assignments through a number of numerical problems, a list of references and suggested readings are given in the unit so that one can go through them for practice. It is important to note that for getting more information on various topics of interest some QR codes have been provided in different sections which can be scanned for relevant supportive knowledge. After the related practical, based on the content, there is a “Know More” section. This section has been carefully designed so that the supplementary information provided in this part becomes beneficial for the users of the book. This section mainly highlights the initial activity, examples of some interesting facts, analogy, history of the development of the subject focusing the salient observations and finding, timelines starting from the development of the concerned topics up to the recent time, applications of the subject matter for our day-to-day real life or/and industrial 1 2 | Introduction applications on variety of aspects, case study related to environmental, sustainability, social and ethical issues whichever applicable, and finally inquisitiveness and curiosity topics of the unit. RATIONALE Bring out the need for biology to be thought as an independent subject and highlight the fundamental importance of observations in any scientific inquiry. PRE-REQUISITES Biology : Basic Biology (Class IX) Physics: Mechanics (Class XII) UNIT OUTCOMES List of outcomes of this unit is as follows: U1-O1: What are the differences and similarities between biology and engineering? U1-O2: Aspects of biology. U1-O3: Why there is a need for biology for engineers. U1-O4: Discoveries made in biology U1-O5: Evolution of biology with the help of engineering. EXPECTED MAPPING WITH COURSE OUTCOMES Unit-1 (1- Weak Correlation; 2- Medium correlation; 3- Strong Outcomes Correlation) CO-1 CO-2 CO-3 CO-4 CO-5 U1‐O1 1 1 - - - U1‐O2 1 1 1 1 1 U1‐O3 2 1 1 1 1 U1‐O4 2 2 2 2 2 U1‐O5 - 2 - 2 1 MA 2  Biology for Engineers | 3 1.1 INTRODUCTION TO BIOLOGY Biology is the study of all aspects of life. In many ways, the last 1000 years have seen a meteoric rise in the study of biology as natural science. For a long time, biology was thought to deal with only the classification of all known living organisms, animal behaviour, and habitats. So, in short, biology is the detailed study of living organisms. This includes the genetic, chemical, physical, ecological and evolutionary aspect of life, in general. The diverse life forms on earth are governed by a few basic facts of life, enlisted as under: 1.1.1 The complexity of biological systems Biological systems have multiple layers on the basis of which life is based on. The intial steps in biology (and other complex sciences) are about identifying, classifying, and describing phenomena. Before delving into explanations for how a biological phenomenon works, it is critical first to describe its characteristics, structure, function, and behaviour. As a result, before the concepts of evolution can be worked out, the classification and associated morphology of various organisms must be considered. The nature of organic chemistry and its interactions to form biological molecules, which eventually assemble to form biological systems whose functioning is based on chemical principles, must be clearly understood. For example, in order to explain and understand why organisms behave the way they do, a detailed classification of life and the organization of molecular elements is required. Furthermore, the complex nature of an ecosystem is better understood if the levels of life are documented using the hierarchy that exists from atom to cell to organism to ecosystem (as in Fig. 1.1). This refers to how organisms evolved, not how biology developed. All living organisms are connected by a chain or web of life forms that affect the present. Changes in the past affect biological evolution like geology, but not chemistry, physics, or math. Biology's mechanisms are similar to chemistry, physics, and math. The properties of living organisms and their relationships to their environments and each other depend on their predecessors' past. Evolutionary processes help "explain" how an organism solves a biological challenge and improves itself to survive and sustain its existence. 1.1.2 Biology looks for a mechanism Biology is much more than just "What is life?" It is also concerned with "How does it work?" On one level, we examine the organs and pieces of an animal or a cell to determine their function in the body. However, biology is also involved at the atomic and molecular level, working out the biochemistry of genes and proteins using the tools of chemistry and physics (as well as math). Such quantitative assessments can now be performed on thousands of genes or proteins in an organism simultaneously. This has spawned a new branch of inquiry known as "Systems Biology," which seeks to discover mechanisms in these massive datasets and describe how hundreds or millions of components interact in a biological system, such as a cell, organism, or population. 3 4 | Introduction Fig 1. 1 Level of organization Commons.wikimedia.org (Creative commons licenses) 1.1.3 Biology is multi-scaled An organism can be studied at a variety of levels, from the atomic and molecular (biochemistry) to the internal structure and functioning of its organs and parts (physiology) to its place in a much larger system across space (ecology) and time (geology). There are two ways to approach the relationship between these scales: reductionism (looking at the smallest possible scale to find an explanation) and emergence (seeing new phenomena emerge as one looks at larger and larger scales). 1.1.4 Biology is integrative Biological phenomena emerge from and must be consistent with chemistry, physics, and math principles. In other words, chemistry and physics govern how an organism can act or evolve. Therefore biologists must grasp how physics and chemistry exhibit themselves in biological organisms and higher-order systems. Increasingly, biologists exploring explanations of complicated natural behaviour are finding it beneficial to use mathematical, physical, and chemical models in their studies. 4  Biology for Engineers | 5 1.2 FUNDAMENTAL SIMILARITIES AND DIFFERENCES The natural and physical world are the subjects of investigation that make up the corpus of knowledge known as science. The use of knowledge to design, construct and manage a product or a process that addresses a problem and satisfies a demand is what engineers refer to as "engineering" (i.e., a technology). A scientific technique is one that is utilized by scientists. The engineering design process is one that engineers employ. A scientist begins by posing a question to the audience. The next step is for them to perform some preliminary research, establish a hypothesis, put that hypothesis to the test through an experiment, evaluate the data, and then report their findings. Engineers begin by describing the problem at hand and then determine the criteria and restrictions, generate ideas, plan, develop technology, and make improvements to their original design. Different pursuits guide the work of scientists and engineers. Scientists aim to explain and comprehend the natural world. Engineers consider a wide range of criteria and limitations when developing solutions to problems, requirements, and preferences to improve the quality of life for people, animals, and the environment. Scientists learn through conducting controlled experiments and long-term observational investigations. The ultimate output may be a study article or a book, and its knowledge can help us understand and forecast the natural world. Engineers create things by using what they know about science. Engineers and scientists are vital in this regard, and each area benefits from the other's innovation and hard work. In certain circumstances, scientists rely on engineering advancements to improve their study (for example, microscopes or monitors). It is critical to assist pupils in comprehending and respecting the differences across the professions to help them realize the various STEM careers and possibilities available to them. A virologist, for example, is a scientist who investigates how viruses travel and how they affect the human body. A biomedical engineer can create a medication that prevents a particular virus from spreading to new cells in the body using the virologist's findings. Even The camera and the eye have more in common than just a similar way of thinking (Fig. 1.2). They both take pictures. The camera's cornea is like a lens, and the retina is like a film. Because of these similarities, the camera looks like it has robot eyes. Even though cameras and eyes have a lot in common, they are not the same. The cornea is the "cap" of the eye. This spherical, see-through structure sits in front of the eye. The lens is made of clear glass and sits in front of a camera. Like corneas, lenses are round. Because the cornea and lens are curved, the eye and camera can only see a small area to the right and left. Without the curve, the eye and camera could only see what's straight ahead. The camera's aperture is similar to the eye's iris, which is just one of many ways the two are alike. The size of the camera's aperture controls how much light gets to the camera's sensor or film. When the iris of the eye gets smaller, the pupil gets smaller and less light gets in. When it's dark, the iris opens, letting more light into the pupil. Apertures that are wider (lower) let in more light than apertures that are narrower (higher). The less light a lens lets in, the more narrow its pupil. The eye and the camera can focus on one thing and blur everything else, no matter how close or far away it is. The eye can focus on a bigger picture, just like a camera with a wider depth of field can take a picture of a big scene. As the eye, the camera has a small field of view. The eye and the lens are shaped in a way that lets them see in the periphery. The scope of the eye is fixed, but lenses can change the camera's scope. To make a 5 6 | Introduction picture, the retina takes in light from the environment. The sensors in both film and digital cameras do the same thing. This is how both cameras and eyes work. Fig 1. 2 Eye and the camera – Similarities and differences in structure and function Do you know? Ken Hibbard, NASA Mission Systems Engineer, shows the one-quarter-scale 3D-printed model of the quadcopter drone named Dragonfly that will land on Titan in 2034. Yet the principles behind dragonfly drones are solid. In fact, NASA has settled on a nuclear-powered autonomous craft called Dragonfly to probe the surface of Saturn’s moon Titan in 2034. NASA’s project is actually a quadcopter rather than a winged drone, but engineers are still convinced they can crack the code of nature’s most gifted flying insect and revolutionize unmanned flight along the way. 1.3 ASPECT OF BIOLOGY AS AN INDEPENDENT SCIENTIFIC DISCIPLINE Biology is a natural science concerned with the study of life composed of many specialized disciplines that study the structure-function growth distribution evolution, and other features of living organisms. However, despite the broad scope of biology, certain general underlying unifying concepts govern all study and research. a. Cell is the basic unit of life b. Genes are the basic unit of heredity c. Evolution accounts for the unity and diversity seen among organisms d. All organisms survive by consuming and transforming energy e. All organisms maintain a stable internal environment 6  Biology for Engineers | 7 All these concepts of life reflect the impossibility of interpreting it as a physicochemical process on physical and chemical concepts. A unique structure and action relationship drive the organic world. Life can be destroyed by disruption of its molecular form; without destruction, a living structure cannot be separated from its surrounding environment or prevented from reproducing. The organic and the inorganic part of the environment are inseparable from an organism, when we study the biology of an organism, the connections with the surrounding micro and macro- environments are also essential. Biological research indicates the first form of life on earth to be microorganisms that existed for billions of years before the evolution of larger organisms. The mammals, birds, and flowers are all relatively recent, originating within the last 200 million years. The first modern appearing humans (Homo sapiens) are also relatively new species, having inhabited this planet for only the last 200,000 years. 1.4 PHILOSOPHY OF BIOLOGY Over the past few decades, there has been a rise in philosophical interest in biology, which reflects the increasing popularity of the biological sciences over the same time period. Because there is now such a large amount of written material on a wide variety of biological subjects, it is difficult to provide a condensed version of this research in a single article like this one. Instead, the purpose of this book is to explain what is meant by "philosophy of biology." Why should philosophers care about biology, and why should biologists care about philosophy? At the end of this topic, a list of the entries in the encyclopaedia that discuss certain issues in the philosophical underpinnings of biology is provided for convenience. Three different kinds of philosophical inquiry fall under the general heading of the philosophy of biology. First, general theses in the philosophy of science are addressed in the context of biology. Second, conceptual problems within biology itself are subjected to philosophical analysis. Third, appeals to biology are made in discussions of traditional philosophical questions. 1.5 HISTORY OF BIOLOGY Biology has been around since the beginning of time, with Aristotle, and Galen from the Greco‐ Roman era being the first people to study biology. Since the advent of Ayurveda, an Indian natural system of medicine, with origins more than 3,000 years ago, Muslim doctors and scholars like Avicenna have improved this old text. During the Renaissance and early modern times in Europe, empiricism and the discovery of new creatures changed how people thought about biology. In physiology, Vesalius and Harvey used experiments and careful observation, while naturalists like Linnaeus and Buffon started putting life, fossils, and the growth and behaviour of organisms into groups. Antonie van Leeuwenhoek's study of microbes with a microscope helped build the foundation for cell theory. Natural history was supported by the growth of natural theology, which was partly a response to mechanical philosophy (although it entrenched the argument from design). In the 18th and 19th centuries, botany and zoology were essential fields of study (Fig. 1.3). Lavoisier and others used physics and chemistry to connect the living world with the 7 8 | Introduction non‐living world. Alexander von Humboldt looked at how species interact with their environment and how this depends on where they live. He did this to lay the foundations for biogeography, ecology, and ethology. Naturalists didn't believe in essentialism and thought about things like extinction and how species can change. The cell hypothesis changed the basics of life. Charles Darwin's theory of evolution by natural selection combines these findings with embryology and palaeontology. At the end of the 19th century, the germ theory of illness took the place of spontaneous generation, but the inheritance was still a mystery. Early in the 20th century, Thomas Hunt Morgan and his students worked on the concepts of genetics using the Drosophila model which led to the Chromosome Theory. After Watson and Crick's theory about the structure of DNA, new fields of study grew quickly. Biology was split into organismal, cellular, and molecular biology after the Central Dogma and the genetic code were broken. By the end of the 20th century, new fields like genomics and proteomics turned this trend around. Organismal biologists started to use molecular tools, and molecular and cell biologists began to study how genes interact with their environment and the genetics of natural populations of organisms. Fig 1. 3 Timeline for important discoveries in biology 1.6 NEED TO STUDY BIOLOGY The study of biology may be found virtually everywhere and in every aspect. You are a part of biology since you are a living entity. Therefore, studying biology is necessary if one is interested in understanding the mechanisms of the human body and those of every other living entity. It is the most effective and genuine method to comprehend the planet around you. 8  Biology for Engineers | 9 The structure, function, growth, origin, evolution, and dispersion of living creatures are the primary topics of investigation for biologists. Along with chemistry and physics, biology is one of the major fields that provides the foundation for everything we know about the natural sciences. A useful framework for organizing the many subfields of biology is to divide the subject into the following four categories: "Biochemistry" refers to the study of the chemical reactions that take place in live things or are connected to living things The interaction of organisms with their respective environments is known as ecology Study of how genes are passed down from parents to kids, as well as how these genes differ from person to person, referred to as Genetics Physiology is the study of biological processes, such as how a particular organ operates, what its role is, and how outside stimuli impact it, Cell biology, environmental biology, evolutionary biology, marine biology, molecular biology, and medical biology are other important subfields that fall under the umbrella of biology. Fig 1. 4 Information table 1.7 OBSERVATIONS THAT LEAD TO IMPORTANT DISCOVERIES IN BIOLOGY The Scottish botanist Robert Brown discovered Brownian Motion in 1827 while looking through a microscope at pollen grains hanging in the water. He was interested in the specific method by which pollen grains fertilize the female ovule. Brown observed that certain plants have oblong pollen grains rather than spherical ones. He reasoned that the grains' unusual structure would 9 10 | Introduction allow him to follow them and determine their role in the impregnation process. His observations of pollen grains moving randomly in water led to the term "Brownian motion," which refers to the random movement of particles in a fluid caused by collisions with other atoms or molecules. Fig 1. 5 Representation of the Brownian motion (Images created using BioRender® software) Thermodynamics is a physics discipline that deals with a system's energy and work. After completing his studies in 1842, German physician Julius Robert Mayer embarked on a voyage to Jakarta as the ship's physician aboard the Dutch three-masted sailing vessel Java. Mayer is supposed to have observed that storm-tossed waves are warmer than the calm sea while aboard a ship, which sparked his interest in physical principles. His questions were about the physical phenomena of warmth and whether the directly produced heat alone (the heat of combustion) or the sum of the direct and indirect amounts of heat produced must be accounted for in the burning process. He also observed that the variation in colour between arterial and venous blood is lower in tropical climates than in temperate ones. He reasoned that at greater temperatures, the human body generates less energy via burning, which led him to the notion of the equivalence between physical effort and heat. In 1842, he finally published his ideas, proposing the general rule of energy conservation and calculating the mechanical equivalent of heat. The two instances just presented are obvious evidence that scientific observations are essential to comprehending and explaining the scientific laws that govern the science of life. Crucial components of a scientific process include making observations, keeping a record of reactions and activities within a system, and applying a scientific perspective to these components to understand the causes of the phenomena being studied. UNIT SUMMARY Biology is the study of living organisms and vital processes. The study of biology is fragmented; however, all branches are united by fundamental principles. Although it is traditional to separate the study of plants (botany) from that of animals (zoology) and structure (morphology) from function (physiology), all living organisms share some biological processes, such as cell division, 10  Biology for Engineers | 11 genetic transfer, and reproduction. In molecular biology, life is considered a manifestation of chemical and energy processes. Typically, biology is organized into fundamental living units. The physicochemical properties of life are examined. Modern interdisciplinary research and the unification of scientific knowledge and investigation have led to substantial overlap between biology and other scientific fields. The disciplines of biochemistry, biomedicine, and biophysics connect chemistry, medicine, and physics to biology. With more sophisticated and accurate laboratory tools and methodologies, it is feasible to comprehend and precisely characterize the ultimate physiochemical organization (ultrastructure) of living matter molecules and how living matter reproduces at the molecular level. Biology helps us comprehend life's essentials. This attribution motivates us to apply the same principles to many gadgets to suit our demands. Scientists have made significant strides in daily operations by monitoring nature and transforming it into usable units. This chapter describes the historical discoveries that have allowed biological science to advance. EXERCISES Multiple Choice Questions 1) ________ discovered Brownian motion. A. Jennifer Doudna and Richard Roblin B. Justin Bieber C. Julius Robert Mayer D. Robert Brown 2) ______ is the most common prokaryotic model organism in Science. A. C. elegans B. Salmonella typhi C. Arabidopsis thaliana D. Escherichia coli 3) Biochemistry is the ______________________________. A. Study of the chemical reactions that take place in live things B. Assembly and interaction of Living things C. Connecti