Unit 1: Introduction to Biology Lecture Notes PDF

Unit-1: Introduction to Biology Lecture 1  Cell Structure & Function http://koning.ecsu.ctstateu.edu/cell/cell.html  Lecture outline 1. History of cell study 2. Basic attributes of cells 3. Cell structures I. The histor...

Unit-1: Introduction to Biology Lecture 1  Cell Structure & Function http://koning.ecsu.ctstateu.edu/cell/cell.html  Lecture outline 1. History of cell study 2. Basic attributes of cells 3. Cell structures I. The history of cell study A. Robert Hooke—1665—coined the word cell, looked at cork cells B. Antonie van Leeuwenhoek Created optics that could visualize single cells His technology “lost” for nearly 200 years  C. Robert Brown—1831—discovered the "nucleus"  I. The history of cell study  D. Theodor Schwann—1838—viewed animal cells in cartilage  1. Cells are the elementary particles of plants and animals  E. Mattias Schleiden—Cells are the fundamental basis of life  F. Virchow—1858—All cells come from cells I. The history of cell study  F. Cell theory 1. All living things are composed of one or more cells What about viruses?  2. Cells are the basic unit of structure and function  3. All cells come from preexisting cells  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  Two Types of Cells Prokaryotic Eukaryotic  Prokaryotic  Do not have structures surrounded by membranes  Few internal structures  One-celled organisms, Bacteria http://library.thinkquest.org/C004535/prokaryotic_cells.html  Eukaryotic  Contain organelles surrounded by membranes  Most living organisms Plant Animal http://library.thinkquest.org/C004535/eukaryotic_cells.html  “Typical” Animal Cell http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif  “Typical” Plant Cell http://waynesword.palomar.edu/images/plant3.gif  Plant or Animal Cell? Found in Plant and Animal cells: Found only in Plant Cells: Nucleus Chloroplasts Golgi Complex Mitochondrion Cell Wall Lyosomes Endoplasmic Reticulum Cell Membrane Ribosomes Vacuoles Cell Parts Organelles Surrounding the Cell  Cell Membrane  Outer membrane of cell that controls movement in and out of the cell  Double layer http://library.thinkquest.org/12413/structures.html Cell Wall  Most commonly found in plant cells & bacteria  Supports & protects cells http://library.thinkquest.org/12413/structures.html 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 http://library.thinkquest.org/12413/structures.html  Chromosomes  In nucleus  Made of DNA  Contain instructions for traits & characteristics http://library.thinkquest.org/12413/structures.html  Nucleolus  Inside nucleus  Contains RNA to build proteins http://library.thinkquest.org/12413/structures.html 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 http://library.thinkquest.org/12413/structures.html  Ribosomes  Each cell contains thousands  Make proteins  Found on ribosomes & floating throughout the cell http://library.thinkquest.org/12413/structures.html  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 http://library.thinkquest.org/12413/structures.html  Golgi Bodies  Protein 'packaging plant'  Move materials within the cell  Move materials out of the cell http://library.thinkquest.org/12413/structures.html  Lysosome  Digestive 'plant' for proteins, fats, and carbohydrates  Transports undigested material to cell membrane for removal  Cell breaks down if lysosome explodes http://library.thinkquest.org/12413/structures.html Vacuoles  Membrane-bound sacs for storage, digestion, and waste removal  Contains water solution  Help plants maintain shape http://library.thinkquest.org/12413/structures.html Chloroplast  Usually found in plant cells  Contains green chlorophyll  Where photosynthesis takes place http://library.thinkquest.org/12413/structures.html MACROmolecules The Big Four Why are Macromolecules important to the Human Body? Macromolecules are essential to the functioning of the human body. ✓ Carbohydrates are the body’s main source of energy. ✓ Lipids provide stored energy reserves. This allows us to survive when carbohydrates are not being supplied to the body. ✓ Protein helps us stay strong, by forming new bones and muscles, and helping us fight diseases. ✓ Nucleic acids are responsible for making each person functional and unique; they are the blueprint for our genetic structure. Objectives Learn Basic Structure and Function of:  Carbohydrates  Lipids  Protein  Nucleic Acids …And Learn The Role of Enzyme Catalysts!  Carbohydrates Are the main energy source of the body! Carbohydrates are formed of carbon, hydrogen, and oxygen atoms with a ratio of 1:2:1. The two categories of carbohydrates include sugar and starch. Glucose is an example of a simple sugar. Carbohydrates are composed of saccharides The smallest unit of saccharides is a monosaccharide. (“Mono” = one) Monosaccharides are also referred to as Simple Sugars Monosaccharides combine together to form disaccharides (“Di” = two) Examples: Lactose & Sucrose Monosaccharides can also form larger carbohydrates such as: Oligosaccharides are chains of 3-10 monosaccharides. (“Oligo” = few) Polysaccharides are the largest unit of carbohydrates (“Poly” = many) Polysaccharides are referred to as complex carbohydrates Starches are polysaccharide chains made from 300 - 1000 glucose units  Carbohydrate Breakdown Enzymes in the mouth, stomach, and small intestine, breakdown the carbohydrate molecules. These large complex carbohydrate molecules breakdown into simple sugars. How Does The Breakdown Occur? Our bodies use special protein molecules called enzymes to break the larger molecules into smaller pieces. Enzymes Are Catalysts [Catalysts are chemicals that quicken a chemical reaction without undergoing any change themselves]  The Role of Enzymes  Activation Energy is the energy needed to start a reaction.  An enzyme is a protein catalyst that speeds up biological reactions by lowering the activation energy!  Some life processes are too slow when they occur on their own, but enzymes help speed them up!  The Role of Enzymes Each enzyme is very specific and only attaches to one type of molecule. The molecule the enzyme acts upon is called its substrate. Variables that impact enzyme activity: 1. Temperature 2. pH Protein Proteins are nutrients which contain materials the body uses for growth and repair. Proteins are made of Carbon, Hydrogen, Oxygen and Nitrogen. Proteins are large molecules made up of combinations of amino acids. Amino Acids Peptides Polypeptides Protein Lysine is an example of an Amino Acid  Amino acids are the building blocks of proteins.  These building blocks bond together to form chains that are called peptides.  Proteins are formed of combinations of large peptides chains, this is referred to as polypeptides.  In order for the body to use protein, enzymes in the stomach and small intestine break the polypeptides down into individual amino acids. Lipids Lipids function as stored energy, insulation for the body, and assist absorption of certain vitamins. Lipids are large molecules that can be categorized as fats or oils. Lipids are composed of triglycerides. These molecules are made up of carbon, hydrogen, and oxygen atoms.  Triglycerides Glycerol + 3 Fatty Acids → Triglyceride Chain of Triglycerides → Lipid Lipid Breakdown Bile and enzymes in the small intestine break lipids down into small molecules of fatty acids and glycerol.  Nucleic Acids ❖ Stores and Carries Genetic Information ❖ Composed of Nucleotides ❖ Unlike the other macromolecules, nucleic acids are not obtained from food Deoxyribonucleic Acid (aka DNA) Is a Nucleic Acid!  NUCLEOTIDES All nucleic acids are made from combinations of nucleotides. There are five nucleotides: uracil, cytosine, thymine, adenine, and guanine Nucleotides are made of three parts: 1. A five-carbon sugar 2. A base that has nitrogen (N) atoms 3. An ion of phosphoric acid known as phosphate (PO43-) YOUTUBE Break! Molecules Gone Wild (Bio Style!)  Thank you Dr. Tarun Pal Assistant Professor School of Bioengineering and Food Technology Shoolini University, Village- Bajhol, Solan (H.P) [email protected]