BiochemistryBiochemistry

the study of chemical reactions of living things

ElementElement

1. Substance that CANNOT be broken down into simpler substances

2. Examples1. 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

AtomsAtoms

1. Elements are made of atoms and each element has a specific atom

2. Structure1. 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.)Atoms (cont.)

4. Every atom of an element has a set # of protons

5. Protons = electrons, which makes atom neutral

6. Compound1. Formed when 2 or more elements

combine

2. Water (H2O) = 2 H atoms and 1 O atom

Chemical BondChemical 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. H2O)

Chemical FormulasChemical Formulas

1. Molecular Formula - # of each kind of atom in a molecule (ex. C6H12O6)

2. Structural Formula – shows how atoms are arranged together

Inorganic vs. Organic Inorganic vs. Organic CompoundsCompounds

1. Inorganic1. Do NOT contain both H & C2. Water (universal solvent), salts,

hydrochloric acid (HCl)

2. Organic1. Contain BOTH H & C2. Large and complex3. Carbohydrates, proteins, lipids and

nucleic acids

CarbohydratesCarbohydrates

1. Used as ENERGY and food storage (starches and sugars)

2. Made of C, H, & O w/2 H’s for every O1. Ex. C6H12O6

MonosaccharidesMonosaccharides

1. Simple sugars (one sugar)

2. Ex. Glucose (C6H12O6)

DisaccharidesDisaccharides

1. Double sugars

2. Ex. Maltose (C12H22O11)

PolysaccharidesPolysaccharides

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 SynthesisDehydration 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 H2O + molecule

3. Hydrolysis – (water-split) add water to split large into small molecule

Dehydration Synthesis-Hydrolysis

ProteinsProteins

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 (NH2), Carboxyl group (COOH) and a Variable group (R)

Protein StructureProtein Structure

Common (R) GroupsCommon (R) Groups1. Hydrophobic (non-polar) - repel water

Common (R) Groups (cont)Common (R) Groups (cont)

1. Hydrophilic (polar) – attracts to water

LipidsLipids1. Fats, oils and waxes2. Source of energy and structure (cell

membrane)3. Fats – lipid solid at room temp4. Oils – lipid liquid at room temp5. Contain C, H & O w/more than 2xs #

of H’s then O’s6. Produced by dehydration synthesis

(lose H2O), made of 1 glycerol and 3 fatty acids

Lipid StructureLipid Structure

Various LipidsVarious 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

EnzymesEnzymes

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

3. Name of enzymes ends in -ase

Enzyme StructureEnzyme 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)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)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 ModelLock 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 Lock and Key / Induced Fit ModelModel

Enzyme Overview

Factors Influencing Enzyme Factors Influencing Enzyme ActionAction

1. Temperature1. 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)Factors (cont)

1. Enzyme – Substrate Concentration1. Rate of action varies w/ amount of

substrate. Rate inc until all enzymes are reacting, then rate levels off

Factors (cont)Factors (cont)

1. pH1. pH scale is a measure of Hydrogen ion

concentration of a solution:1. pH = 7 neutral

2. pH > 7 base 3. pH < 7 acid

2. Each enzyme has a certain pH where it functions most efficiently

1. Enzymes in blood = neutral

2. Enzymes in stomach = acidic

Factors (cont)Factors (cont)