bio chap 1 and 2

atom

Smallest particle of an element

proton

positively charged particle, atomic number

neutron

no charge

electron

negatively charged particle

nucleus

Center of an atom

valence electrons

electrons in the outermost shell, most energy

compound

substance w 2 or more elements

element

pure substance w one type of atom

atomic number

number of protons

mass number

protons + neutrons

isotope

Atoms of the same element that have different numbers of neutrons

ionic bonds

transfer of electrons

ions

Charged atoms

covalent bonds

sharing of electrons

polar

imbalanced charges, mixes with water due to electronegativity

nonpolar

equal sharing of electrons

electronegative

the ability of an atomt to attract electrons

hydrogen bonds

weak attraction between a hydrogen atom and another atom

hydrophillic

water loving

hydrophobic

water hating

soluble

able to dissolve

insoluble

incapable of being dissolved

cohesion

an attraction between molecules of the same substance

adhesion

an attraction between molecules of different substances

high specific heat

water resists changes in temperature

high heat of vaporization

many hydrogen bonds must be broken for water to evaporate

surface tension

A measure of how difficult it is to stretch or break the surface of a liquid

solution

homogeneous mixture

solute

substance being dissolved

solvent

the substance in which the solute dissolves

acidic solution

pH below 7

basic solution

pH above 7

dehydration synthesis reaction

uses water to link

hydrolysis reaction

uses water to separate

isomers

same atoms but different arrangement

functional groups

an atom or group of atoms within a molecule that has similar chemical properties whenever it appears in various compounds

polymer

many monomers linked together

carbohydrate

source of energy

glycosidic linkage

a covalent bond formed between 2 monosaccharides by a dehydration reaction

lipids

fats, store energy

phosphodiester bond

In nucleic acids, the 5' 3'

protein

amino acids

peptide bond

covalent bond formed between amino acids

polypeptide

chain of amino acids

denature

protein losing its shape and functionality due to temperature or pH

primary structure

amino acid sequence

secondary structure

alpha helix or beta sheet

tertiary structure

one protein, the circles

quarternary structure

2+ polypeptide subunits

disulfide bridges

covalent bonds that reinforce the shape of a protein

hydrophobic interactions

weak, hydrophobic molecules grouping together to avoid water