Biochemistry the study of chemical reactions of living things

Element 1. Substance that CANNOT be broken down into simpler substances 2. Examples 1. Carbon = C 2. Hydrogen = H 3. Oxygen = O 4. Nitrogen = N 5. Sulfur = S 3. Most common elements in living things = C,H,O,N

Atoms 1.Elements are made of atoms and each element has a specific atom 2.Structure 1.Nucleus has (+) charged protons and neutral charged neutrons 2.Orbiting nucleus are (-) charged electrons 3.Atoms differ in the number of protons, neutrons and electrons they have

Atoms (cont.) 4. Every atom of an element has a set # of protons 5. Protons = electrons, which makes atom neutral 6. Compound 1. Formed when 2 or more elements combine 2. Water (H 2 O) = 2 H atoms and 1 O atom

Chemical Bond 1. Forms when elements combine by transferring / sharing electrons 2. Ionic Bond – atom loses/gains an electron it becomes a +/- charged ion. Now can bind with opposite charged ion (ex. NaCl) 3. Covalent Bond – formed when atoms share electrons (ex. H 2 O)

Chemical Formulas 1. Molecular Formula - # of each kind of atom in a molecule (ex. C 6 H 12 O 6 ) 2. Structural Formula – shows how atoms are arranged together

Inorganic vs. Organic Compounds 1. Inorganic 1. Do NOT contain both H & C 2. Water (universal solvent), salts, hydrochloric acid (HCl) 2. Organic 1. Contain BOTH H & C 2. Large and complex 3. Carbohydrates, proteins, lipids and nucleic acids

Carbohydrates 1. Used as ENERGY and food storage (starches and sugars) 2. Made of C, H, & O w/2 H’s for every O 1. Ex. C 6 H 12 O 6

Monosaccharides 1. Simple sugars (one sugar) 2. Ex. Glucose (C 6 H 12 O 6 )

Disaccharides 1. Double sugars 2. Ex. Maltose (C 12 H 22 O 11 )

Polysaccharides 1. Chains of sugars 2. Starch – food storage in plants 3. Cellulose – makes up cell walls in plants 4. Glycogen – food storage in animals

Dehydration Synthesis 1. Process where simple molecules are joined together to form larger molecules by removing water 2. Removes H from one and OH from another to form H 2 O + molecule 3. Hydrolysis – (water-split) add water to split large into small molecule Dehydration Synthesis-Hydrolysis

Proteins 1. Enzymes, hormones and structural parts of cells, made up of amino acids 2. Structure of Amino Acid (aa) 1. Contain C, H, O &N and some contain sulfur 2. Made of amino group (NH 2 ), Carboxyl group (COOH) and a Variable group (R)

Protein Structure

Common (R) Groups 1. Hydrophobic (non-polar) - repel water

Common (R) Groups (cont) 1. Hydrophilic (polar) – attracts to water

Lipids 1. Fats, oils and waxes 2. Source of energy and structure (cell membrane) 3. Fats – lipid solid at room temp 4. Oils – lipid liquid at room temp 5. Contain C, H & O w/more than 2xs # of H’s then O’s 6. Produced by dehydration synthesis (lose H 2 O), made of 1 glycerol and 3 fatty acids

Lipid Structure

Various Lipids 1. Waxes – Lipids w/ alcohol and fatty acids (no glycerol) 2. Saturated Fat – has all of the H’s it can hold 3. Unsaturated Fat – has some double bonds so it is NOT “full” of H’s

Enzymes 1. Special proteins needed for chemical reactions in living things 2. ALL enzymes are catalysts 1. change rate of reaction but are NOT changed or used up 2. Enzyme Action Enzyme Action 3. Name of enzymes ends in -ase

Enzyme Structure 1. Large complex protein 2. Folded in a certain way so it fits w/ the substrate (the molecule it reacts with) 1. Where it fits together is the active site ENZYME SUBSTRATE

Enzyme Structure (cont) SUBSTRATE COENZYME ENZYME SUBSTRATE COENZYME ENZYME 1. Some contain a non-protein part called a coenzyme, usually a vitamin 2. This causes the shape of the enzyme to change, so it can now fit with the substrate

Enzyme Structure (cont) Primary Structure – sequence of amino acids made as the chain is made at the ribosome Secondary – coiling and folding produced by hydrogen bonding Tertiary – overall shape of polypeptide (folds and coils) determined by interactions of R groups Quaternary – shape of protein when made of multiple polypeptides

Lock and Key Model 1. Active site has a unique shape so it can ONLY bind with ONE type of substrate (key in a lock) 2. Substrate becomes attached to enzyme (enzyme-substrate complex) and enzyme either breaks it apart or binds two substrates together 3. After the reaction, the product(s) and enzyme break apart and enzyme can now bind with another substrate

Lock and Key / Induced Fit Model Enzyme Overview

Factors Influencing Enzyme Action 1. Temperature 1. Rate increases w/ inc temp until a certain temp is reached, then rate dec 2. High temp changes enzyme’s shape so it can no longer bind to substrate, dec rate of reaction (denaturation) 3. Human enzymes’ optimum temp = 37ºC, reactions slow down at 40ºC

Factors (cont) 1. Enzyme – Substrate Concentration 1. Rate of action varies w/ amount of substrate. Rate inc until all enzymes are reacting, then rate levels off

Factors (cont) 1. pH 1. pH scale is a measure of Hydrogen ion concentration of a solution: 1. pH = 7neutral 2. pH > 7 base 3. pH < 7acid 2. Each enzyme has a certain pH where it functions most efficiently 1. Enzymes in blood = neutral 2. Enzymes in stomach = acidic

Factors (cont)