AP Biology Review Unit I - Chemistry of Life

Antiparellel

referring to the arrangement of the sugar-phosphate backbones in a DNA double helix

alpha helix

A coiled region constituting one form of the secondary structure of proteins, arising from a specific pattern of hydrogen bonding between atoms of the polypeptide backbone (not the side chains).

amino acids

monomers of proteins

amino group

A functional group that consists of a nitrogen atom bonded to two hydrogen atoms

beta pleated sheet

One form of the secondary structure of proteins in which the polypeptide chain folds back and forth, or where two regions of the chain lie parallel to each other and are held together by hydrogen bonds.

branched carbohydrate

Examples: amylopectin, glycogen

Calorie

Amount of energy needed to raise temperature 1 gram of water 1 degree C

carbohydrate

Energy-rich organic compound, such as a sugar or a starch, that is made of the elements carbon, hydrogen, and oxygen.

Carbon

an element that can bond with many elements and form unlimited chains, 4 bonding sites

carboxyl terminus

the free carboxyl group at one end of a polypeptide

Cellulose

polysaccharide consisting of glucose monomers that reinforces plant-cell walls

Chitin

A structural polysaccharide, consisting of amino sugar monomers, found in many fungal cell walls and in the exoskeletons of all arthropods.

Cohesion

Attraction between molecules of the same substance

Covalent bonds form when

electrons are shared between two atoms

dehydration synthesis

A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.

Denaturation

loss of normal shape of a protein due to heat or other factor

disaccharides

Carbohydrates that are made up of two monosaccharides, sucrose, lactose maltose

disulfide bonds

Strong chemical side bonds formed when the sulfur atoms in two adjacent protein chains are joined together.

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

fatty acids

unbranched carbon chains that make up most lipids

Fibrous proteins (structural proteins)

Extended and strand-like proteins. Examples: keratin, elastin, collagen, and contractile fibers

globular proteins

these are compact, generally rounded, and soluble in water.

Glucose

A simple sugar that is an important source of energy.

glycerol

A three-carbon alcohol to which fatty acids are covalently bonded to make fats and oils.

Glycogen

An extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch.

heat

The energy transferred between objects that are at different temperatures

hydrogen bond

weak attraction between a hydrogen atom and another atom

Hydrogen Group

H

Hydrolysis

the chemical breakdown of a compound due to reaction with water.

Hydrophobic

Having an aversion to water; tending to coalesce and form droplets in water.

Hydrophilic

Having an affinity for water.

hydroxyl group

A chemical group consisting of an oxygen atom bonded to a hydrogen atom.

Isomer

Compounds with the same formula but different structures.

kilocalorie (kcal)

A quantity of heat equal to 1,000 calories. Used to measure the energy content of food, it is usually called a "Calorie."

kinetic energy

the energy an object has due to its motion

Lactose

glucose + galactose (milk sugar)

Lipids

Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.

Macromolecules

A very large organic molecule composed of many smaller molecules

Monomer

a molecule that can be bonded to other identical molecules to form a polymer.

Monosaccharides

Single sugar molecules

Nitrogen

Most abundant gas in the atmosphere

nitrogenous base

is a carbon ring structure that contains one or more atoms of nitrogen. In DNA, Adenine, Thymine, Cytosine, Guanine.

nonpolar

No partial charges. Do not mix with water.

Nucleotide

monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

peptide

Short chain of amino acids linked by peptide bonds

peptide bond

covalent bond formed between amino acids C-N

phosphate group

A chemical group consisting of a phosphorus atom bonded to four oxygen atoms; important in energy transfer.

phosphate

element found in nucleic acids, phospholipids

Phopholipids

They serve as a major structural component of most biological membranes. They form the lipid bilayer in cell membranes of organisms.

polar covalent bond

A covalent bond in which electrons are not shared equally

polar molecule

A molecule that has electrically charged areas.

Polymers

large compound formed from combinations of many monomers

Polypeptide

long chain of amino acids that makes proteins

primary structure of protein

sequence of amino acids

Protein

A three dimensional polymer made of monomers of amino acids.

function of proteins

essential for the growth, development, and repair of all body tissues

function of carbohydrates

provide energy

function of lipids

long term energy storage

function of nucleic acids

store and transmit genetic information

Ribose

A five-carbon sugar present in RNA

quaternary structure

Union of 2+ polypeptide subunits

RNA

single-stranded nucleic acid that contains the sugar ribose

saturated fats

fats that are solid at room temperature and saturated with hydrogen. Butter

secondary structure of protein

protein structure is formed by folding and twisting of amino acid chain

specific heat

The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree celcius

Sucrose

table sugar, disaccharide

surface tension

the uneven forces acting on the particles on the surface of a liquid

Temperature

A measure of the average energy of motion of the particles of a substance.

tertiary structure

Results from interactions between side chains.

thermal energy

The total energy of all the particles of an object.

unsaturated fats

fats that remain liquid at room temperature