BCH 201: General and Medical Biochemistry Lecture 1 (2024) PDF

MADUKA UNIVERSITY ,EKWEGBE-NNSUKA WELCOME TO BCH 201 :GENERAL AND MEDICAL BIOCHEMISTRY BY DR.J. E. OGUCHE 211st October,2024.  Course Compact Course Code: BCH 201 Course Title: GENERAL AND...

MADUKA UNIVERSITY ,EKWEGBE-NNSUKA WELCOME TO BCH 201 :GENERAL AND MEDICAL BIOCHEMISTRY BY DR.J. E. OGUCHE 211st October,2024.  Course Compact Course Code: BCH 201 Course Title: GENERAL AND MEDICAL BIOCHEMISTRY ❖Introduction BCH 201 -GENERAL AND MEDICAL BIOCHEMISTRY ❖AIM: The aim of this course is to build your foundation in the knowledge of biochemistry as it relates to the proper physiological functioning of the human system ❖Lectures ❖Attendance ❖Assignment, Home work ❖Quiz ❖TERM Paper ❖Presentation (group) ❖C.A ❖Exam  COURSE CONTENTS Introduction to biochemistry The cell theory, structure and functions of major cell components Cell types, constancy and diversity Cell organelle of prokaryote and eukaryotes Chemical composition of cells Centrifugation and methods of cell fractionation Structure, function and fractionation of extra cellular organelles Water, total body water and its distribution Regulation of water and electrolyte balance Acidity and alkanality, PH and PK values and their effects on cellular activities  REFERENCES/FURTHER READING ❖Amanullah, M. (2011). Medical Biochemistry and Biotechnology. (1 st ed.). ❖Murray, R.K., Bender, D. A., Botham, K., M., Kennelly, P.J., Rodwell V.W. & Well, P.A. (2012). Harper’s Illustrated Biochemistry (29th ed.). McGraw-Hill Medical. ❖ Nelson, D.L. & Cox M. M. (2009). Lehninger Principles of Biochemistry (4 th ed ❖Devlin T.M. (2010) Textbook of Biochemistry with Clinical Correlation 7 th Edition. John Wiley & Sons Inc. Murray, ❖ R. K., Bender, D. A., Botham, K., M., Kennelly, P.J., Rodwell V. W. and Well, P. A. (2012). Harper‟s Illustrated ❖ Biochemistry (29th Edition) McGraw-Hill Medical. Sadler, T. W. (2004). Langman‟s Medical Embryology 9th edition. REFERENCES/FURTHER READING ❖Lehninger Principles of Biochemistry by Nelson and Cox. ❖Textbook of Biochemistry with Clinical Correlations by Thomas M. Devlin. ❖Harper’s Biochemistry Principles of Biochemistry by McKee and McKee. ❖Visit the Library for Encyclopædia ❖Britannica, Journals, Periodicals etc.  INTRODUCTION BCH 201 title “General Biochemistry” is a two (2) Unit course with 4 modules and (10) Units. Biochemistry is the study of biomolecules. It can also be defined as the application of chemistry to the study of biological processes in living organisms. Biochemistry is both a life science and a physical (chemistry) science It explores the chemistry of living organisms and the molecular basis for the changes occurring in living cells.  INTRODUCTION (Cont’d) Millions of complex chemical reactions are going on in the human body at any given time, ranging from the balance of the endocrine system to the storage and utilization of fuel molecules such as glucose. By studying and understanding this highly complex reaction, biochemists have found better ways to fight infections and diseases not just at the molecular level but also at the cellular level. Since an Engineer cannot repair a vehicle if he does not understand how it works, so a biochemist must understand how the human body functions and the various mechanisms involved in process. Much of biochemistry also deals with the structures and functions of cellular components such as proteins, carbohydrates, lipids and nucleic acids collectively known as biomolecules.  INTRODUCTION (Cont’d) The main purpose of all the efforts of Biochemistry is to benefit humans in all forms particularly in the diagnosis and treatment of different diseases. For example, investigation of diabetes mellitus is completely based upon the laboratory test in Biochemistry laboratories, where the presence of sugar in urine is tested by Benedict‟s test. Similarly, investigations of other disorders such as albuminuria, lactosuria, etc are a few of so many ailments that are investigated in Biochemistry laboratories.  LEARNING OBJECTIVES In this course, you will learn about the branches of biochemistry and its relevance to other life sciences, biochemistry of living cells, biological oxidation and electron transport chain, buffer, acidity, alkalinity, pH, pKa values and their roles in cellular metabolism. The knowledge that will be acquired in this course will assist you in understanding the various biochemical reactions that takes place in the living system. understand the metabolism of major biomolecules such as carbohydrate, proteins, lipids as well as nucleic acid.  LET GET START DEFINITION CONT’D ❖ Biochemistry is a hybrid science involved with the study of chemical reactions or processes taking place in living organisms. ❖It is neither pure biology nor pure chemistry, but a hybrid of both. ❖Biochemistry (BCH) can also be defined as a science that explains life in molecular terms HISTORICAL PERSPECTIVES OF BIOCHEMISTRY Relevance of Biochemistry to other life Sciences The essence of studying biochemistry is for the purpose of understanding the various chemical reactions that occur in living organisms at both the cellular and molecular levels. Biochemistry as a life science is applicable and relevant in different fields of study such as medicine, agriculture, pharmacy, nursing etc. ✓Biochemistry provides foundation for other life sciences such as medicine, nursing, pharmacy, zoology, Physiotherapy microbiology etc. as well as agriculture. ✓In pharmacy biochemistry provides an understanding of the constitution of drugs, the half-life of drugs and drug metabolism as it helps in the prevention and treatment of diseases. Relevance of Biochemistry to other life Sciences ✓In agriculture, the knowledge of biochemistry plays a valuable role in farming, fishery, poultry, sericulture etc ✓gives an idea of how the use of fertilizers can increase plants growth, their yield and quality of food ✓can help to evaluate pesticide residues or other toxic waste in plants, food grain and seed through biochemical test ✓help in the monitoring of the quality of milk in animal husbandry which can be checked by biochemical test. ✓In medicine, biochemistry gives an insight into the changes and physiological alterations that take place in the body. ✓ It also assists in clinical diagnosis of diseases. Biochemists have contributed greatly to the discovery of new drugs to treat chronic diseases such as cancer, viral infections and metabolic disorders.  What about this? QUIZ: 3MINS State five relevance of biochemistry in nursing science and physiotherapy Mention five key biochemical concepts in nursing and physiotherapy Various Aspects (Branches) of Biochemistry Medical Biochemistry Industrial Biochemistry Xenobiochemistry (Drug Toxicology) Food Biochemistry (Microbial Chemistry and Fermentation) Nutritional Biochemistry Molecular Biology/Bioinformatics Forensic Biochemistry Oncology (Cancer research) Plant Biochemistry Enzymology Membrane Biochemistry Biotechnology  Branches of Biochemistry i. Toxicology: This field studies the adverse effects of toxic or foreign chemical substances on the organisms. Environmental and food toxicology also fall under this branch of biochemistry. ii. Enzymology: This is the study of enzymes, their functions, deficiency and the consequence of such deficiency in diseases. iii. Molecular biology and Biotechnology: This field evolved directly from Nucleic acid biochemistry and it involves manipulation of DNA to improve drug research and solve health problems. It has wide applications in other fields of science which includes cancer research. iv. Lipid and Carbohydrate biochemistry: This field studies the biochemical basis of metabolic disorders such as diabetes, obesity and Cardiovascular diseases. v. Natural products biochemistry: This is a new area of research in biochemistry; it evolved as a result of interest of scientists across the world in searching for new drugs from plants. Quinine and Artesunate (antimalarial drugs) were isolated from plants Some Common Terminologies in used BCH ❖Metabolism :is comprehensive network of chemical reactions occurring within the living organisms. A + B ----> C ---> D + E ❖ Metabolites- products of metabolism ❖Metabolism --- Anabolism and catabolism ❖Reaction Pathway (or simply, pathway) ❖Cells, Tissues, Organ, system ❖Amino acid, amino acid sequence ❖Gene, nucleotide sequence (or gene sequence), ❖Enzymes ❖ATP (Adenosine 5‘-triphosphate)-- the major chemical form of energy used in living organisms for carrying out work or activities within the body. HOME WORK Write a short note on cell discovery and cell theory. Mention five component of a prokaryote cell and their functions  CELL DISCOVERY AND CELL THEORY; How were cells discovered? The first description of the cell is generally attributed to Robert Hooke (1635-1702), an English physicist who was also a distinguished microscopist. In 1665 Hooke published Micrographia, the first important work devoted to microscopical observation, and showed what the microscope could mean for naturalists. He described the microscopic units that made up the structure of a slice of cork and coined the term ‘‘cells’’ or ‘‘pores’’ to refer to these units.  CELL THEORY Although Hooke thought of the cork cells as passages for fluids involved in plant growth), the modern term ‘cell’ came directly from his book. Is there a Bridge between life and ‘non-life’ forms? The theory of Spontaneous generation (also called Abiogenesis)--- by Aristotle (flies or fleas from dust, maggot from dead flesh, rats from old dirty clothes, etc) The theory of Biogenesis by Louis Pasteur. Louis Pasteur's 1859 experiment is widely seen as having settled the question of spontaneous generation. He boiled a meat broth in a flask that had a long neck that curved downward, like that of a goose or swan. The idea was that the bend in the neck prevented falling particles from reaching the broth, while still allowing the free flow of air. The flask remained free of growth for an extended period. When the flask was turned so that particles could fall down the bends, the broth quickly became clouded)  Formulation of the Cell Theory In 1838, the botanist Matthias Jakob Schleiden (1804–1881) suggested that every structural element of plants is composed of cells or their products. The following year, a similar conclusion was elaborated for animals by the zoologist Theodor Schwann (1810–1882). He stated that “the elementary parts of all tissues are formed of cells” and that “there is one universal principle of development for the elementary parts of organisms... and this principle is in the formation of cells”. The conclusions of Schleiden and Schwann are considered to represent the official formulation of ‘cell theory’ and their names are almost as closely linked to cell theory as those of Watson and Crick with the structure of DNA. Later works in the 1850s by Robert Remak (1815–1865), Rudolf Virchow (1821– 1902) and Albert Kölliker (1817–1905) who showed that cells are formed through scission of pre-existing cells. Virchow’s aphorism omnis cellula e cellula (every cell from a pre- existing cell) thus became the basis of the theory of tissue formation, even if the mechanisms of nuclear division were not understood at the time.  Postulations of the Cell Theory Credit for the formulation of this theory was eventually given to German scientists Theodor Schwann, Matthias Schleiden, and Rudolph Virchow. The Cell Theory states: 1) All living organisms are composed of cells. They may be unicellular or multicellular. 2) The cell is the basic unit of life. 3) Cells arise from pre-existing cells. The cell theory emphasized the concept of the unity of life and brought about the concept of organisms as “republics of living elementary units”. The modern version of the Cell Theory includes the ideas that: 4) Energy flow occurs within cells. 5) Heredity information (DNA) is passed on from cell to cell. 6) All cells have the same basic chemical composition. CELL STRUCTURE, COMPONENTS OF THE CELL AND THEIR FUNCTIONS ❖The living cell we are to discuss here is not different from the cell you learnt in Biology when you were in secondary school. ❖ Cells are the basic building blocks of all living organism. ❖The human body is composed of trillion of cells. Cells have many parts, each with a different function. ❖Some of these parts called organelles are specialized structures that perform certain tasks within the cell. ❖Biochemical arrangement of cells and how these cells interact to perform various functions in man are not only fascinating but also very interesting.  Definition of Cell A cell is the smallest unit that is capable of performing life functions.  Examples of Cells Amoeba Proteus Plant Stem Bacteria Red Blood Cell Nerve Cell  COMPONENTS OF THE CELL ❖Imagine the sensitivity of cells responsible for taste; different region of your tongue detects different taste. ❖Some cells are replaced every 72 hours in our body while some spend up to ten years before they die. ❖Also, some cells remain in our body throughout our lifetime.  TYPE OF CELL There are two basic types of cells in nature and these are prokaryotic and eukaryotic cells. Prokaryotic cells are the simplest cells and are without a nucleus and cell organelles Eukaryotic cells are sophisticated cells with a well- defined nucleus and cell organelles. A group of cells forms tissue, various tissues forms an organ and different organs make system that make up the body ASSIGNMENT NO1 In Tabular form, state five differences and similarity between prokaryotic and eukaryotic cells  Prokaryotic Do not have structures surrounded by membranes Few internal structures One-celled organisms, Bacteria  Eukaryotic Contain organelles surrounded by membranes Most living organisms Plant Animal  Structure of Animal Cell A living cell is defined as the fundamental unit of life and it is the smallest unit capable of exhibiting the characteristics of life. The cell was discovered in 1665 by Robert Hooke while examining a thin slice of cork under his new crude microscope. He observed numerous porous structures and named it the cell. Structure of Animal Cell Figure 1: Structure of the animal cell Typical Plant Cell  CELL DIVERSITY AND CONSTANCY Cells are not identical – they diversify their structure to suit their function. The animal cells have different shapes and sizes; some are circular, spherical, cylindrical, fibrous etc. Red blood cells called erythrocytes are one of the smallest animal cells while ova are among the largest. In terms of length, nerve cells are the longest. For ease of representation, circular structure is commonly used to illustrate the structure of the animal cell. DIVERSE KINDS OF CELLS Red Blood Cells Nerve Cells Muscle Cells  Cell constancy: The condition in which the entire body of an adult animal or plant consists of a fixed number of cells that is the same in all members of the species. This phenomenon is also called eutely. Eutelic organisms have a fixed number of somatic cells when they reach maturity, the exact number being relatively constant for any one species. This phenomenon is also referred to as cell constancy. Development proceeds by cell division until maturity; further growth occurs via cell enlargement only.  MAIN PARTS OF A CELL A cell can be subdivided into 3 parts namely: i. The plasma membrane ✓This is the thin cover that separates a cell from its environment. ✓It also protects the components of the cell from leakage. ✓It prevents the fluid outside the cell called extracellular fluid (ECF) from mixing with the fluid inside the cell called intracellular fluid (ICF). ✓Plasma membrane regulates the materials that enters or leaves the cell, for this reason, it is said to be semi- permeable. ✓ In addition, the plasma membrane has some glycoproteins and glycolipids on its surface; these molecules serve as signal molecule between cells.  MAIN PARTS OF A CELL Cont’d ii. The cytoplasm: This is the fluid-like space between the plasma and nuclear membrane. Cytoplasm is the cavity where the organelles are found. It provides space for the movement of synthesized products from one compartment to another for further processing. The organelles are suspended in the cytoplasm by cytoskeleton network that resemble nets. iii. Nucleus: This is the most important part of the cell, the nucleus is always centrally located. It has its own membrane called nuclear membrane which protects the content of the nucleus. Nucleus is very important to the cell because it contains the genetic materials (DNA and RNA) that control all the activities of the cell. Nucleus regulates the rate and time of cell division. It also determines the materials that enter or exit the cell.  Functions of cell organelles i. Rough Endoplasmic Reticulum: ✓ It is a vast system of interconnected, membranous, sacks that are located in the cell's cytoplasm ✓Responsible for the synthesis of protein (due to the presence of ribosomes attached to it) and degradation of worn out organelles. ii. Smooth Endoplasmic Reticulum: ✓It is located in the cell's cytoplasm and transports materials throughout the cell. ✓It contains enzymes which produce and digest lipids (fats) and membrane proteins. ✓The smooth endoplasmic reticulum is therefore responsible for the synthesis of lipids and steroids, storage and metabolism of calcium and detoxification of toxic substances. Functions of cell organelles; surrounding the cell 1. Cell Membrane Outer membrane of cell that controls movement in and out of the cell Double layer 2. Cell Wall Most commonly found in plant cells & bacteria Supports & protects cells Inside the Cell  Inside the Cell Nucleus Directs cell activities Separated from cytoplasm by nuclear membrane Contains genetic material - DNA  Nuclear Membrane Surrounds nucleus Made of two layers Openings allow material to enter and leave nucleus Chromosomes In nucleus Made of DNA Contain instructions for traits & characteristics  Nucleolus Inside nucleus Contains RNA to build proteins  Cytoplasm Gel-like mixture Surrounded by cell membrane Contains hereditary material Endoplasmic Reticulum Moves materials around in cell Smooth type: lacks ribosomes Rough type (pictured): ribosomes embedded in surface  Ribosomes Each cell contains thousands Make proteins Found on ribosomes & floating throughout the cell  Mitochondria Produces energy through chemical reactions – breaking down fats & carbohydrates Controls level of water and other materials in cell Recycles and decomposes proteins, fats, and carbohydrates  Golgi Bodies Protein 'packaging plant' Move materials within the cell Move materials out of the cell  Lysosome Digestive 'plant' for proteins, fats, and carbohydrates Transports undigested material to cell membrane for removal Cell breaks down if lysosome explodes  Vacuoles Membrane-bound sacs for storage, digestion, and waste removal Contains water solution Help plants maintain shape  Chloroplast Usually found in plant cells Contains green chlorophyll Where photosynthesis takes place  Functions of cell organelles CONT’D iii. Golgi Apparatus: ✓ It is a flattened sac-like organelle that looks like a stack of pancakes. It is located near the nucleus. ✓ It produces the membranes that surround the lysosomes. ✓ The golgi apparatus packages proteins and carbohydrates into membrane- bound vesicles for export from the cell. iv. Lysosome: ✓ These are round organelles surrounded by a membrane where the digestion of cell nutrients takes place due to presence of the digestive enzymes. ✓ It contains more than 40 different hydrolytic enzymes and they are collectively known as LYSOZYMES which are actively involved in the degradation of macromolecules, worn out organelles and the removal of excess secretory products. ✓ Lysosome has the thickest membrane to prevent the leakage of hydrolytic enzymes. v. Peroxisomes: ✓ These are single membrane spherical organelles, also called micro-bodies. ✓ They contain antioxidant enzymes such as catalase and peroxidases which are involved in the detoxification of hydrogen peroxide and other radicals  Functions of cell organelles CONT’D Vi. Mitochondria: ✓The mitochondrion is known as the power house of the cell as it generates energy in form of ATP (adenosine triphosphate), the energy currency of all living cells. ✓It is spherical in shape and has double membrane i.e. inner and outer mitochondrion membrane. vii. Ribosomes: ✓These are small organelles rich in ribonucleic acid (RNA) and are active in the synthesis of proteins. ix. Vacuole: ✓ The vacuole is a fluid-filled, membrane-surrounded cavity inside a cell. ✓ The vacuole fills with food being digested and waste material that is on its way out of the cell. ✓There are specialized vacuoles which function to store fat as fat droplets. BASIC CHEMICAL COMPOSITION OF CELLS Proteins (These exist either as dipeptides, tripeptides, or polypeptides) e.g glutathione, albumin, enzymes etc. Carbohydrates (These exist either as monosaccharides, disaccharides, polysaccharides or both) e.g glucose, sucrose, starch, cellulose etc. Lipids [Fats (unsaturated fatty acids), Oils (Saturated fatty acids) or both] e.g Oleic acid, palmitic acid Water (either in low or high volume) Nucleic acids [These are found in the body either as DNA or RNA (mRNA, tRNA, rRNA)]