HUMANBIOLOGY_CHAPTERTWO

substance that takes up space and is made of atoms

matter

a pure substance consisting of atoms containing a characteristic number of protons

element

a particle of matter; composed of protons, neutrons, and electrons

atom

a particle in an atom’s nucleus carrying a positive charge

proton

a particle in an atom’s nucleus that is electrically neutral

neutron

central part of an atom

nucleus (atom)

a negatively charged particle that makes up part of an atom

electron

the total number of protons and neutrons in an atom’s nucleus

mass number

any of the forms of an element, each having a different number of neutrons in the nucleus

isotope

two or more atoms joined by chemical bonds

molecule

volume of space where a particular electron is likely to be

orbital

attraction between oppositely charged ions

ionic bond

type of chemical bond in which two atoms share electrons

covalent bond

weak chemical bond between opposite partial charges on two molecules or within one large molecule

hydrogen bond

the attraction of water molecules to one another

cohesion

a chemical in which other substances dissolve, forming a solution

solvent

a chemical that dissolves in a solvent, forming a solution

solute

a mixture of a solute dissolved in a solvent

solution

interaction in which bonds break and new bonds form

chemical reaction

neither acidic nor basic

neutral (solution)

the result of a chemical reaction

product

compound containing both carbon and hydrogen

organic molecule

a long molecule composed of similar subunits (monomers).

polymer

a single unit of a polymer

monomer

compound containing carbon, hydrogen, and oxygen in a ratio 1:2:1

carbohydrate

a polymer consisting of amino acids and folded into its functional three-dimensional shape

protein

an organic molecule consisting of a central carbon atom bonded to a hydrogen atom, an amino group, a carboxyl group, and an R group

amino acid

a carbon atom double-bonded to an oxygen and single-bonded to a hydroxyl group

carboxyl group

a nitrogen atom single-bonded to two hydrogen atoms

amino group

an amino acid side chain

R group

a covalent bond between adjacent amino acids; results from dehydration synthesis

peptide bond

a long polymer of amino acids; it is called a protein once it folds into its functional shape

polypeptide

a long polymer of nucleotides; DNA or RNA

nucleic acid

genetic material consisting of a double helix of nucleotides, each containing the sugar deoxyribose

DNA (deoxyribonucleic acid)

nucleic acid typically consisting of a single strand of nucleotides, each containing the sugar ribose

RNA (ribonucleic acid)

hydrophobic organic molecule consisting mostly of carbon and hydrogen

lipid

supply or store energy; structural support

function: carbohydrate

carry out nearly all the work of a cell

function: protein

store energy; component of membranes

function: lipid

store and use genetic information, and transmit it to the next generation

fuction: nucleic acids