AP Biology Final Review: Chemistry of Life and Cells

Water Structure

One oxygen atom bonded to two hydrogen atoms.

Polar Molecule

Molecule with uneven distribution of charge.

Tetrahedral Shape

Molecule shape with four bond sites available.

Hydrogen Bonding

Attraction between partially positive and negative charges.

Electronegativity

Tendency of an atom to attract electrons.

Cohesion

Attraction between molecules of the same kind.

Adhesion

Attraction between molecules of different kinds.

Surface Tension

Liquid's surface resistance to rupture under stress.

Hydration Shell

Layer of water molecules around dissolved solute.

Dissociation

Process of a compound breaking into ions.

Specific Heat Capacity

Energy to raise 1g of substance by 1°C.

Heat of Fusion (∆Hf)

Energy required to melt 1g of substance.

Heat of Vaporization (∆Hv)

Energy needed to evaporate 1g of substance.

pH Scale

Measures acidity or alkalinity from 0 to 14.

Arrhenius Acid

Substance that increases [H+] in solution.

Arrhenius Base

Substance that increases [OH-] in solution.

Bronsted-Lowry Acid

Substance that donates protons (H+).

Bronsted-Lowry Base

Substance that accepts protons (H+).

Amphoteric

Substance that can act as acid or base.

Strong Acid Examples

HCl, H2SO4, HBr, HI, HNO3, HClO3.

Strong Base Examples

LiOH, NaOH, KOH, Ca(OH)2, Sr(OH)2.

Buffer

Minimizes changes in H+ and OH- concentration.

Homogeneous Mixture

Uniform mixture with no visible separation.

Heterogeneous Mixture

Mixture with visibly different substances.

Solute

Substance dissolved in a solvent.

Solvent

Substance that dissolves the solute.

Concentration

Amount of solute in a solvent at given temperature.

Saturation

Maximum concentration of solute in solution.

Supersaturated Solution

Contains more dissolved solute than normally possible.

Solubility

The amount of solute that dissolves in a certain amount of a solvent at a given temperature and pressure to produce a saturated solution.

Molarity

The concentration of a solution expressed in moles (mol) of solute/liter (L) of solution.

Molarity (M)

mol of solute/L of solution.

Atmospheric CO2

CO2 diffuses into water and reacts with it → H2CO3 which releases H+ and HCO3-.

Ocean Acidification

As seawater acidifies, H+ ions combine with carbonate ions to produce bicarbonate.

Carbonate

Required for calcifications (production of calcium carbonate) by many marine organisms, including reef-building corals.

Carbohydrates

Carbon + hydrate; provide energy for the body.

Sugars/Monosaccharides

Monomers of carbohydrates.

Disaccharides

2 monosaccharides together.

Polysaccharides

Polymers of carbohydrates.

Cellulose

Makes up the cell walls of plants.

Chitin

Makes up the exoskeleton of arthropods/insects (arthropoda) & cell walls of fungus.

Starch

Composed of amylose & amylopectin found in plants.

Glycogen

Composed of amylose & amylopectin found in animals (stored in liver and skeletal muscle).

Insulin

Secreted by pancreas to turn glucose into glycogen (stored in the liver).

Glucagon

Secreted by the pancreas to turn glycogen into glucose (in the bloodstream).

Glycosidic bond

Bonds between monosaccharides.

Lipids

Fats and oils that are insoluble and hydrophobic.

Fatty Acid

Hydrocarbon with a carboxyl group at the end.

Cis vs Trans

Cis - both hydrogens are on the same side; Trans - each hydrogen is on a different side.

Glycerol

Tertiary alcohol compound.

Phospholipid

Lipid with phosphate group; has a hydrophilic (polar) head and hydrophobic (nonpolar) tails.

Amphipathic Structures

Have both a hydrophilic and hydrophobic part.

Cholesterol

A compound from which sex hormones are synthesized & stabilizes cell membrane in extreme temperatures.

Testosterone

Male sex hormone.

Estradiol

Female sex hormone.

Adipose tissue

Beneath the skin in the form of stored fat.

Ester bond

The bond between lipids or glycerol and a fatty acid.

Saturated fat

Solid fat that is closely packed together, forming solid fat like butter & coconut oil.

Unsaturated fat

Liquid fat like olive oil & vegetable oil.

Proteins

Structural components of everything in the body.

Keratin

Protein that is present in bull horns and human nails.

Collagen

Protein that provides fibrous framework in animal connective tissue.

Receptor proteins

Proteins that signal from one cell to another in a matter of nanoseconds.

Insulin (regulation)

A hormonal protein secreted by the pancreas that regulates blood sugar concentration.

Enzymes

biological catalysts

Most enzymes

are proteins and end in 'ase'

Catalyzing chemical reactions

by speeding them up

Factors that influence rate

Work best at 98.6 F or 37 C in humans

Low temp

works too slowly

High temp

changes shapes and doesn't serve function anymore

pH

pH changes throughout your body

Concentration of Enzyme/Substrate

Enzymes work best when there is excess of enzyme/substrate

Coenzymes

Like vitamins & minerals that help enzyme function properly

Example of Coenzyme

Iron & hemoglobin enzyme

Enzyme-substrate complex

enzyme + substrate

Lock & Key Model

mold of enzyme fits exactly to substrate

Induced Fit Model

enzyme adapts to the shape of the substrate like 'Play-doh'

Ribozyme

RNA acts as an enzyme

Inhibitors

Competitive - binds to active site blocking the substrate

Non-competitive Inhibitors

binds to the allosteric site and changes the shape of the protein → blocks the substrate

Actin/Myosin

protein fibers responsible for muscle contractions

Antibodies

proteins that help get rid of viruses and bacteria

Casein

protein found in milk that is a major source of amino acids

Ovalbumin

protein found in eggs that is a major source of amino acids

Hemoglobin

a protein that transports oxygen and carbon; found in RBCs

Amino Acids

monomers of proteins

Zwitterion

Carboxyl group is acidic, amino group is basic, so net charge is neutral

20 different types of amino acids

The variable/R group changes in each of the 20

Polypeptides

polymers of proteins

Peptide bond

between amino acids

C/Carboxyl terminal

the end of a peptide chain where the carboxyl group is left unlinked

N/Amino terminal

the end of a peptide chain where the amino group is left unlinked

Primary Protein Structure

Linear sequence of amino acids

Secondary Protein Structure

Linear chain can orient itself into: alpha (α) helix & beta (β) pleated sheet

Tertiary Protein Structure

any protein achieving its biological use

Chaperonins

tertiary proteins that help other proteins fold into 3-dimensional structure and maintain it

Conformation

term for 3-dimensional structure of a protein

Quaternary Protein Structure

Multiple tertiary structures are joined together and function as a unit

Prions

abnormally folded proteins that can act as infectious agents

Denaturation

shape of protein changes if pH or temperature is changed