Biology Unit 2 Keywords

Front 1

activation energy

Back 1

the energy barrier that must be overcome for a reaction to occur

Front 2

active site

Back 2

the place on an enzyme where the substrates attach and the reaction occurs

Front 3

adenine

Back 3

a nitrogen-containing base that is part of one of the types of nucleotides that make up DNA or RNA; pairs with thymine and uracil

Front 4

adenosine triphosphate

Back 4

ATP; the molecule that delivers usable chemical energy for almost all processes and reactions that a cell must undergo to survive

Front 5

adhesion

Back 5

an attraction between the molecules of one substance and the molecules of another substance

Front 6

amino acids

Back 6

the organic molecules that serve as the units from which proteins are made

Front 7

aqueous

Back 7

watery

Front 8

atom

Back 8

a tiny particle that is the fundamental building block of all substances and whose properties determine the properties of an element made up only of those atoms

Front 9

bioluminescence

Back 9

light produced by a living organism

Front 10

carbohydrates

Back 10

one of the four major classes of large organic molecules made from carbon, oxygen, and hydrogen

Front 11

catalyst

Back 11

a substance present during a chemical reaction that speeds up the reaction but is not used up or changed during the reaction

Front 12

cohesion

Back 12

an attraction between molecules of the same substance

Front 13

covalent bond

Back 13

a bond in which electrons are shared between the bonded atoms

Front 14

cytosine

Back 14

a nitrogen-containing base that is part of one of the types of nucleotide that makes up DNA or RNA; pairs with guanine

Front 15

deoxyribose

Back 15

a monosaccharide; the sugar component of DNA

Front 16

DNA

Back 16

deoxyribonucleic (dee-AHK-sih-riy-boh-nyoo-KLEE-ihk) acid; this is the molecule, unique to each individual, carrying the genetic information to be found in every cell; all the information an organism needs to live and reproduce is contained in its DNA

Front 17

electron

Back 17

a tiny part of an atom with a negative electrical charge

Front 18

element

Back 18

a chemical substance that contains only one kind of atom and that cannot be broken down into simpler substances

Front 19

entropy

Back 19

the randomness of any physical system

Front 20

enzyme

Back 20

a protein that is a catalyst for chemical reactions in organisms; it increases the rate of the reaction without being used up or changed

Front 21

guanine

Back 21

a nitrogen-containing base that is part of one of the types of nucleotide that makes up DNA or RNA; pairs with cytosine

Front 22

hemoglobin

Back 22

a large molecule that captures oxygen from the lungs and delivers it to the rest of the body

Front 23

hydrogen bond

Back 23

the force of attraction between a partially charged atom and a hydrogen atom that is covalently bonded to another partially charged atom

Front 24

hydrophilic

Back 24

water loving; soluble in water

Front 25

hydrophobic

Back 25

water hating; not soluble in water

Front 26

inorganic compound

Back 26

a compound not formed from carbon-hydrogen bonds; more generally, a compound not produced by a living thing

Front 27

ion

Back 27

an atom that has a positive or negative electrical charge

Front 28

ionic bond

Back 28

the force of attraction between a charged atom (or group of connected atoms) and another with the opposite charge

Front 29

lipid

Back 29

fats, oils, phospholipids, steroids, and waxes; one of four major classes of large organic molecules

Front 30

matter

Back 30

anything that takes up space and has mass; the three usual forms of matter are solid, liquid, and gas

Front 31

molecule

Back 31

any compound resulting from covalent bonding

Front 32

neutron

Back 32

a neutral particle with approximately the same mass as a proton, found in nuclei of atoms along with protons

Front 33

nitrogenous

Back 33

containing nitrogen

Front 34

nucleic acids

Back 34

one of the four major classes of large organic molecules, which are important in storing, transmitting, and making useful the information necessary for the processes of life

Front 35

nucleotide

Back 35

a subunit of a nucleic acid that consists of a phosphate group, a five-carbon sugar, and a nitrogenous base

Front 36

organic compound

Back 36

any chemical compound that contains carbon bonded to at least one other atom, usually hydrogen

Front 37

peptide

Back 37

a compound of two or more amino acids

Front 38

polar molecule

Back 38

a molecule in which there are positive and negative areas

Front 39

polypeptide

Back 39

a chain of hundreds or thousands of amino acids

Front 40

proteins

Back 40

one of the four major classes of large organic molecules, made of amino acids

Front 41

proton

Back 41

a positively charged particle found in the nuclei of atoms

Front 42

ribose

Back 42

a monosaccharide; the sugar component of RNA

Front 43

RNA

Back 43

acid; nucleic acid that uses the instructions stored in DNA to build proteins

Front 44

solute

Back 44

a substance that dissolves in solvent

Front 45

solvent

Back 45

a substance in which something is dissolved

Front 46

substrate

Back 46

A molecule on which enzymes act

Front 47

surface tension

Back 47

the force that holds molecules together on the surface of a liquid

Front 48

thymine

Back 48

a nitrogen-containing base that is part of one of the types of nucleotide that makes up DNA; pairs with adenine

Front 49

trace element

Back 49

a chemical element present in minute quantitites that is essential for the proper working of an organism

Front 50

uracil

Back 50

a nitrogen-containing base that is part of one of the types of nucleotide that makes up RNA; pairs with adenine

Front 51

valence electrons

Back 51

the electrons in any atom´s outer level