AP Biology: Unit 1 Terms - Chemistry of Life

amino acid

monomer that makes up proteins; contains carboxyl and amino functional groups

ATP (adenosine triphosphate)

energy storing molecule in cells composed of an adenosine molecule, a ribose sugar and 3 phosphate groups energy is stored in the molecules chemical bonds and can be used quickly and easily by cells

carbohydrate

a class of energy giving nutrients that includes sugars, starches, and fiber; composed of one or more simple sugars bonded together

carbon

C, atomic number 6, has 4 valence electrons to form covalent bonds; found in all biological molecules

cellulose

polysaccharide consisting of glucose monomers that reinforces plant-cell walls; humans cannot digest cellulose because we lack the digestive enzymes needed to break the B1,4 linkage in cellulose

complementary base pairing

Hydrogen bonding between particular pyrimidines and purines. Adenine & Thymine. Cytosine & Guanine.

dehydration reaction

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

denatured

when a protein loses its secondary tertiary structure it loses function, destroyed by high temps that change their pH and can no longer function properly

deoxyribose

five-carbon sugar that is a component of DNA nucleotides

disaccharide

A double sugar, consisting of two monosaccharides joined by dehydration synthesis, A molecule composed of two monosaccharides; such as maltose, sucrose, and lactose.

DNA (deoxyribonucleic acid)

A nucleic acid found in all living cells which carry the organisms hereditary information; consists of nucleotides called A adenine T thymine G guanine C cytosine

enzyme

specialized proteins that speed up chemical reactions

fat

organic molecule that contains fatty acids and glycerol; found in adipose tissue of vertebrates which protects body organs, insulates body, and stores energy in the body

fatty acid

a long carbon chain carboxylic acid; vary in length and in the number and location of double bonds; linked to a glycerol molecule form fat.

functional group

An assemblage of atoms commonly attached to the carbon skeletons of organic molecules and usually involved in chemical reactions and behaves in a predictable way

glucose

a monosaccharide found in all living cells; it has the chemical formula C6 H12 O6; the form of sugar that circulates in the blood and provides the major source of energy for body tissues; it degrades as a source of energy during cellular respiration

glycerol

Three-carbon carbohydrate with three hydroxyl groups; component of fats and oils.

glycogen

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

hexose

a six-carbon sugar

a common example is glucose or fructose

hydrogen bonding

the intermolecular force in which a hydrogen atom that is bonded to a highly electronegative atom is attracted to an unshared pair of electrons of an electronegative atom in a nearby molecule

Ex: between water molecules
Ex: between nitrogen bases in DNA

hydrolysis reaction

Reaction in which a covalent bond between two subunits is broken through the addition of the equivalent of a water molecule; a hydrogen atom is added to one subunit and a hydroxyl group to the other.

hydrophilic

Having an affinity for water; readily absorbing or dissolving in water.

hydrophobic

Repelling, tending not to combine with, or incapable of dissolving in water.

lipid

macromolecule made mainly from carbon and hydrogen atoms that tends to be soluble in nonpolar solvents; includes fats, oils, and waxes

monomer

small molecular unit that is the building block of a larger molecul

monosaccharide

single sugar molecule (monomer), such as fructose or glucose; carbohydrate that cannot be decomposed by hydrolysis

nucleic acid

an organic compound, either RNA or DNA, whose molecules are made up of one or two chains of nucleotides and carry genetic information

nucleotide

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

oil

A common name for a triglyceride that is a liquid at room temperature and contains a high percentage of unsaturated fatty acids; composed of glycerol and three fatty acids

organic chemistry

the chemistry of compounds containing carbon (originally defined as the chemistry of substances produced by living organisms but now extended to substances synthesized artificially)

organic molecule

A molecule that contains only carbon and any of the following: hydrogen, oxygen, nitrogen, sulfur, and/or phosphorous

pentose

any monosaccharide sugar containing five atoms of carbon per molecule; five-carbon sugar that is one of three subunits composing nucleotides;

Ex: ribose (found in RNA)
Ex: deoxyribose (found in DNA - has 1 less O than ribose)

peptide bond

A covalent bond that links amino acids together in a protein; the amino group and carboxyl group from two amino acids are linked through dehydration synthesis to form a peptide bond

phospholipid

a lipid that contains phosphorus and that is a structural component in cell membranes; a molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail

polarity

A lack of electrical symmetry in a molecule. Charge differences on opposite ends of a structure. Ex: water is polar molecule

polymer

large molecule made up of small repeating units linked by covalent bonds to from a long chain, a naturally occurring or synthetic compound consisting of large molecules made up of a linked series of repeated simple monomers

polypeptide 

A polymer (chain) of many amino acids linked together by peptide bonds.

polysaccharide

any of a class of carbohydrates whose molecules contain chains of monosaccharide molecules, large carbohydrate made up of monosaccharides, ex. starch and glycogen

protein

an organic compound that is made of one or more chains of amino acids and that is a principal component of all cells

ribose

a five-carbon monosaccharide found in RNA (ribonucleic acid)

RNA (ribonucleic acid)

A type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually single-stranded; functions in protein synthesis and as the genome of some viruses.

saturated fatty acid

a fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, thus maximizing the number of hydrogen atoms that can attach to the carbon skeleton.

starch 

A storage polysaccharide found in the roots of plants and certain other cells; a polymer of glucose.

steroid

a type of lipid that consists of four carbon rings to which various functional groups are attached and that usually has a physiological action; examples are cholesterol, testosterone, and estrogen.

triglyceride

3 fatty acids (chains of hydrocarbons) bonded to a glycerol, most fats are eaten and absorbed in this form, carbohydrate

unsaturated fatty acid

A fatty acid possessing one or more double bonds between the carbons in the hydrocarbon tail. Such bonding reduces the number of hydrogen atoms attached to the carbon skeleton.

water

H2O, a polar compound made of one oxygen (electronegative) and two hydrogens (positive)