Bio Ch. 2

Front 1

atoms

Back 1

the smallest units that retain the properties of an element

Front 2

proton

Back 2

carries a positive charge, or a defined amount of electricity, sybolized as p+
, an atoms nucleus holds one or more protons

Front 3

neutrons

Back 3

neutrons have no charge.

Front 4

electrons

Back 4

these zip around the nucleus which carry a negative charge, symbolized e-

Front 5

these balance each other

Back 5

protons p+, and electrons e+,

*an atom that has the same number of electrons and protons has no electrical charge.

Front 6

atomic number

Back 6

the number of protons in the nucleus of its atoms. For example, the atomic number for hydrogen, which has one proton is 1. For carbon, with six protons, its atomic number is 6.

Front 7

mass number

Back 7

the total number of protons and neutrons in the atomic neucleus. For example, carbon, with 6 p+ and 6 n, has a mass number of 12.

Front 8

periodic table

Back 8

the elements are organized according to their atomic number. Those in the same column have the same number of electrons

Front 9

inert elements

Back 9

none of their electrons is available for chemical interaction

Front 10

number of elements that occur naturally on earth

Back 10

92

Front 11

He discovered radioactivity

Back 11

Henri Becquerel

Front 12

isotopes

Back 12

one of two or more forms of an element that differ in the number of neutrons and their neuclei

Front 13

superscript

Back 13

number to the left of an elements symbol is the isotopes mass number (combined number of protons and neutrons)

Front 14

too many or too few neutrons in the nucleus can cause this

Back 14

to be unstable or radioactive

Front 15

radioactive decay

Back 15

the process when a radioactive atom spontaneously emits energy as subatomic particles and xrays when its nucleus disintegrates

Front 16

tracers

Back 16

a certain type of molecule in which a radioisotope gets substituted for a stable element in that molecule

Front 17

orbitals

Back 17

volumes of space around the nucleus

Front 18

an atoms number of electrons is the same amount of

Back 18

protons

Front 19

lyse

Front 20

metabolism

Back 20

the many chemical reactions that occur in organisms

Front 21

mutagens

Back 21

a chemical or physical agent that interacts with DNA and causes mutation

Front 22

mutations

Back 22

a change in the nucleotide sequence of DNA; the ultimate source of genetic diversity

Front 23

name three parts of a nucleotide

Back 23

an organic monomer consisting of a 5-carbon sugar covalently bonded to a nitrogenous base and a phosphate group.

Front 24

NFL

Back 24

a control mechanism in whick a chemical reaction, metabolic pathway, or hormone secreting gland is inhibited by the products of the reaction, pathway, or gland. As the concentration of the products builds up, the product molecules themselves inhibit the process that produce them

Front 25

non polar covalent bond

Back 25

an attraction between atoms that share one or more pairs of electrons equally because the atoms have similar electronegativity

Front 26

noncompetative inhibition

Front 27

Organelles

Back 27

a structure with a specialized function within a cell

Front 28

osmosis

Back 28

the passive transport of water across a selectively permeable membrane

Front 29

osmotic pressure

Front 30

phagocytosis

Back 30

cellular "eating"; a type of endocytosis whereby a cell engulfs macromolecules, other cells, or particles into its cytoplasm

Front 31

phospholipied

Back 31

a molecule that is a constituent of the inner bilayer of of biological membranes, having a polar , hydrophilic head and a non polar hydrophibic tail

Front 32

pinocytosis

Back 32

cellular "drinking", a type of endocytosis in which the cell takes fluid and dissolved solutes into small membranous vesicles

Front 33

plasma

Back 33

the liquid matrix of the blood in which the blood cells are suspended

Front 34

polar covalent bond

Back 34

an attraction between atoms that share electrons unqually. The shared electrons are pulled closer to one atom, making it partially negative and the other atom patrially positive.

Front 35

receptor-mediated endocytosis

Back 35

the movement of specific molcules into a cell by the inward budding of membranous vesicles. The vesicles contain proteins with receptor sites specific to the molecules being taken in.

Front 36

reverse transcriptase

Back 36

an enzyme that catalyzes the synthesis of DNA on an RNA template

Front 37

RNA

Back 37

ribonucleic acid. A type of nucleic acid consisting of nucleotide monomers with a ribsoe sugar and the nitrogenous bases ACGU. Usually single stranded, functions in protein synthesis as the genome of some viruses

Front 38

solute

Back 38

a substance that is dissolved in a solution

Front 39

solvent

Back 39

the dissolving agent in a solution. Water is the most versatile known solvent.

Front 40

Watson & Crick

Front 41

what is the difference btwn prokaryotic and eukaryotic cells and plant and animal cells