Organic compounds: contain C Organic Inorganic compounds: no C - PDF document

2/18/2013 CHEMISTRY OF CELLS • 11 elements make up all organisms • C, O, N, H: 96% weight of human body • Organic compounds: contain C Organic • Inorganic compounds: no C Chemistry • Carbon: one of most important of elements - 4 valence electrons: can have 4 bonds - Bonds with O, N, P, S as well as C - Variable structural combinations Bonding and Structural Formulas Carbon Structural Formations H and He : 2 valence electrons to complete outer shell Chains All other elements : 8 valence electrons to complete outer shell Branches Rings 4 Classes of Organic Compounds Polymerization : process of forming large (biomolecules) compounds from small compound 1. Carbohydrates monomer : single unit dimer : two monomers 2. Lipids polymer : three or more monomers macromolecules : extremely large polymers 3. Proteins 4. Nucleic Acids 1

2/18/2013 Types of Carbohydrates CARBOHYDRATES 1. Monosaccharides : (C 6 H 12 O 6 ) (saccharo / Latin or Greek /sweet or sugar) A. glucose – most important : used for energy - all di/polysaccharides broken down into glucose B. galactose – milk C. fructose – fruits - composed of C : H : O 1 : 2 : 1 ratio - function: energy and structure 2. Disaccharides: (C 12 H 22 O 11 ) two monosaccharide units Isomers A. sucrose – table sugar B. maltose – malt sugar (beer) Compounds that have same chemical formula but differ in the arrangement of groups around the carbon atoms (glucose + glucose) C. lactose – milk sugar 3. Polysaccharides : very large saccharide chains Building and Breaking Organic Molecules (poly / Greek many) Cellulose Dehydration synthesis/ Hydrolysis Condensation splitting of polysaccharide A. starch – energy storage for plants into monosaccharide units - 100’s of glucose molecules chemically joining two with consumption of water molecules with loss of H2O B. glycogen – energy storage for animals (muscles and liver) C. cellulose – structure for plant stems - wood and bark - cell walls of plants **Molecules of starch, cellulose, and glycogen- 1000s of glucose units, no fixed size** 2

2/18/2013 LIPIDS (fats) Formation of a Triglyceride via Dehydration Synthesis • waxy or oily compounds • ratio of H to C is > 2:1 • structure: 1 glycerol (alcohol) + 3 fatty acids + 3 H 2 O lost • functions: - energy storage - membrane formation (phospholipids) - chemical messengers (sterols/steroids) Types of Lipids PROTEINS • Saturated - solid at RT - most important of biomolecules - max number of H bonds - composed of C, O, H, and N with C (saturated with bonds) - functions: 1. structure, growth , repair • 2. carrier molecules Unsaturated - liquid at RT 3. enzymes- initiate chemical - double bonds between C reactions 4. immunity- antibodies • Polyunsaturated - many double 5. receptors- initiate and bonds between C receive messages between - cooking oils cells - structure: amino acids : building blocks ** trans fats : heating unsaturated fats to become saturated - very bad NH2 amino group (base) COOH carboxyl group (acid) ** hydrogenated oils : adding H to R functional group (determines a.a.) unsaturated fats to make solid - very bad Amino Acid R Groups (differentiate each amino acid) Functional Group Group that determines the nature of a molecule ALANINE GLYCINE PHENYLALANINE 3

2/18/2013 Structure of Proteins Peptide Bond - Covalent bond between two amino acids Primary : sequence of amino acids in polypeptide chain - Dehydration synthesis reaction Secondary : folds or twists in the protein chain (usually alpha helix or beta sheets) - H from amino group bonds ( most common - DNA) with OH (hydroxyl) of Tertiary : globular or spherical due to another amino acid more complex folds determines protein’s function - water molecule is (ex: myoglobin, enzymes) removed Quarternary : two more tertiary forms animation combined (hemoglobin ) Nucleic Acids Nucleic Acids - composed of C, O, H, N plus P DNA : master molecule RNA : involved in of organisms protein synthesis - very large molecules - polymers of nucleotides ATP (adenosine triphosphate) - Single nucleotide with two extra energy storing phosphate groups. - energy from broken down food is stored temporarily in ATP - cells need ATP to function ENERGY AND CHEMICAL REACTIONS ENERGY AND CHEMICAL REACTIONS Oxidation/ Reduction Reactions (Redox): reactions in which - All organisms need energy to carry on life processes electrons are transferred between atoms Energy : the ability to move or change matter - Oxidation : reactant loses one or more electrons (to do work) becomes positively charged - Forms: heat, electrical, light, sound, chemical, etc - Reduction : reactant gains one or more electrons - Energy can be stored or released by chemical becomes negatively charged reactions (bonds are broken) 4

2/18/2013 ENERGY AND CHEMICAL REACTIONS Biochemical pathway products of one reaction are used as reactants of Activation energy : amount of energy needed to next reaction start a reaction - due to redox reactions Types of Reactions Catalyst : substance that speeds up chemical reaction without being changed or used up 1. Endothermic/ Endergonic : absorbs energy Product moves to a higher energy state Ex: ice  water Lowers activation energy 2. Exothermic/ Exergonic: releases energy Product moves to a lower energy state Ex: steam  water Enzyme Mode of Action Models Enzyme : biological catalyst (ends in “ ase ”) - up to 200 types in each cell Lock and Key Model - globular proteins - specific catalytic action Ex: lipase: lipids lactase: lactose amylase: starch  glucose - abnormal conditions cause reduced activity : dependent on environment - needed to maintain homeostasis - mode of action : enzyme substrate complex 5

2/18/2013 Enzyme Model of Action Models Factors that affect enzyme activity Induced Fit Model temperature: (humans 35 – 40*C) 1. pH: (humans 6 – 8) 2. 1. Enzyme has pocket (active 3. Enzyme active site changes shape to fit substrate site) in structure. (induced fit). DENATURED ENZYME Chemical reactions occur and new products are made. 4. New products are released. 2. Only one substrate fits into Enzyme returns to original shape to be used again. the active site of enzyme molecule. Enzyme animation denatured enzyme animation Study for the test!! HOW ENZYMES ARE USED IN MEDICINE Protease inhibitors: AIDs virus - virus needs HIV protease to complete protein synthesis - protease inhibitors fits into substrate and prevents enzyme from binding - prevents protein synthesis and production of more virus 6