Biology Ch 2

Front 1

atom

Back 1

basic unit of matter

Front 2

nucleus

Back 2

center of atom, protons and neutrons form it

Front 3

electron

Back 3

neg. charged particle which is in constant motion, in the space surrounding the nucleus

Front 4

element

Back 4

a pure substance that consists entirely of one type of atom

Front 5

isotope

Back 5

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

Front 6

compound

Back 6

a substance formed by the chemical combination of two or more elements in definite porportions

Front 7

ionic bond

Back 7

formed when one or more electrons are transferred form one atom to another

Front 8

ions

Back 8

positively and neg. charged atoms

Front 9

covalent bond

Back 9

forms when electrons are shared between atoms

Front 10

molecule

Back 10

smallest unit of most compounds

Front 11

Van der Waals forces

Back 11

when molecules are close together, a slight attraction can develop between the oppositely charged regions of nearby molecules

Front 12

cohesion

Back 12

attraction between molecules of the same substance

Front 13

adhesion

Back 13

an attraction between molecules of diff. substances

Front 14

mixture

Back 14

a material composed of two or more elements or compounds that are physically mixed together but not chemically combined

Front 15

solution

Back 15

a mixture of two or more substances in which the molecules of the substances are evenly distributed

Front 16

solute

Back 16

the substace disolved

Front 17

solvent

Back 17

substance in which the solute is disolved

Front 18

suspensions

Back 18

mixture of water and nondisolved water

Front 19

pH scale

Back 19

meausurment system to indicate the concentration of H+ ions in a solution

Front 20

acid

Back 20

any compound that forms H+ ions in a solution

Front 21

base

Back 21

compound that produces hydroxide ions in a solution

Front 22

base

Back 22

a compound that produces hydroxide ions in a solution

Front 23

buffer

Back 23

weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH

Front 24

monomer

Back 24

it is a small unit that can join togetha with other small units to form polymers

Front 25

polymer

Back 25

it is a larger compound formed from the combinations of many monomers

Front 26

carbohydrate

Back 26

a compound made up of carbon, hydrogen, and oxygen atoms

Front 27

monosacharide

Back 27

they are single sugar molecules

Front 28

polysaccharides

Back 28

large macromoleucles formed from monosaccharides

Front 29

lipids

Back 29

made mostly from carbon and hydrogen atoms

Front 30

nucleic acids

Back 30

macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus

Front 31

nucleotides

Back 31

consist of three parts: a 5-carbon sugar, a phosphate group, and a nitrogeneous base

Front 32

ribonucleic acid

Back 32

a single-stranded nucleic acid that contains the sugar ribose

Front 33

deoxribonucleic acid

Back 33

a nucleic acid that contains sugar deoxyribose

Front 34

amino acid

Back 34

a compound with an amino acid group on one end and a carboxyl group on the other end

Front 35

proteins

Back 35

macromolecules that contain nitrogen as well as carbon, hydrogen, and oxygen