Miller and Levine Biology Chapter 02 Chemistry of Life

Chapter 2 notes from miller& levine biology text book

atom

the basic unit of matter

proton

positivly charged part of an atom in the nucleus

neutron

part of atom with no charge in the nucleus

electron

negatively charged particle of an atom that orbits around the nucleus and is 1/1840 the size of a proton

nucleus

center of the atom; contains protons and neutrons

element

a pure substance with only one type of atom

isotopes

atoms of the same element that differ in the number of neutrons

compound

two or more elements chemicaly combined

ionic bonds

when one or more electrons are transferred from one atom to the other

covalent bonds

when electrons are shared between two atoms

molecule

smallest unit of most compounds

van der Waals forces

slight attraction that develops between oppositely charged regions of nearby molecules

polar molecule

one end is positive, the other is negative

hydrogen bonds

can hold water molecules; weak bond; not as strong as chemical bonds but strongest a molecule can form

cohesion

attraction between molecules of the same substance

adhesion

attraction between molecules of different substances

mixture

two or more elements or compounds physically mixed but not chemically combined; and it can be separated

solution

type of mixture in which all the components are evenly distributed; example-water and a dissolved substance

solute

substance that is dissolved in a solution

solvent

dissolving substance in a solution

suspension

mixture of water and a non-dissolved material

pH scale

scale that describes how acidic or basic a substance is; measures the concentration of H+ ions in a solution, scale between 0-14

acid

0-6.5 on the pH scale; compound that forms hydrogen ions in solution

base

7.5-14 on the pH scale; compound that produces hydroxide ions in solution

neutral substance

7 on the pH scale

buffer

weak acids or weak bases that prevent sharp, sudden changes in pH; a way to control pH levels

monomer

small chemical unit that makes up a polymer

polymer

molecule composed of many monomers; makes up macromolecules

carbon

an element that can bond with many elements and form unlimited chains

macromolecules of life

large molecules formed from many small molecules (carbohydrates, lipids, nucleic acids, proteins)

carbohydrates

major source of energy for most living things; also used for structural support and protection

monosaccharide

single sugar

polysaccharide

many sugars linked

lipids

used to store energy; form important parts of biological membranes; form waterproof coverings; includes- fats, oils, and waxes

nucleic acids

store and transmit genetic information; examples- RNA and DNA; made of nucleotides

nucleotides

a monomer consisting of a 5-carbon sugar, a phosphate group, and a nitrogenous base

proteins

function to control the rate of reactions and regulate cell processes; help transport substances into or out of cells; help fight disease; form important cellular structures; made of amino acids

chemical reaction

process that changes or transforms elements or compounds

reactant

what goes into the reaction

product

what comes out of a chemical reaction

activation energy

the energy needed to start a chemical reaction

catalyst

speeds up the rate of a chemical reaction

enzyme

a protein catalyst in living things that speeds up reactions in cells

substrate

reactant of an enzyme-catalyzed reaction