Ch 2 And 3 Biology

Front 1

matter

Back 1

anything that occupies space and has mass

Front 2

element

Back 2

form of matter cannot be broken down into sumpler form by ordinary chemical means

Front 3

atom

Back 3

smallest particles that can exist an still maintain the properties of an element

Front 4

nucleus

Back 4

central portion of an atom containing virtually all its mass made of 2 dif types of small particles

Front 5

protons

Back 5

+ charge, number cannot change in nucleus

Front 6

atomic number

Back 6

number of protons in nucleus, used an identifying characteristic of atoms, number of which cannot change

Front 7

neutrons

Back 7

uncharged particles in the nucleus number of which can change from one atom to another

Front 8

isotope

Back 8

atoms in which # of nuetrons has been changed, often radioactive or fluorescent which allows them to be used in nucleur medicine

Front 9

atomic mass

Back 9

# of protons and neutrons in an atom, value is changable by adding or subtracting neutrons

Front 10

electron cloud

Back 10

outer portion of an atom occupying all of an atom's space but havng no mass. 2 dif atoms can band together by sharing portions of their clouds

Front 11

electrons

Back 11

extremely small changed particles surrounding the nucleus moving at set distances and in a particular path around the nucleus

Front 12

ions

Back 12

atoms with electric charge formed by gaining or losing electrons

Front 13

orbitals

Back 13

pathways electrons folow as they move around the nucleus-2 atoms sharing an orbital forming a powerful bond between them

Front 14

molecule

Back 14

paticles formed by 2 or more atoms sharing electrons or being attracted by other forces

Front 15

covalent bonds

Back 15

most powerful type of molecular bond created by 2 or more atoms sharing at least one other oribtal between them

Front 16

organic compounds

Back 16

make up the majority of living cells solid mass and carry out metabloic functions that keep cells alive

Front 17

nucleic acids

Back 17

DNA and RNA found mainly in the nucleus of a cell responsible for controlling a cell's activities by controlling the production of protein and are responsible for passing traits from one generation to the next

Front 18

nucleotide

Back 18

basic unit of nucleic structure made of a phosphate group of simple sugar ad one of 4 different chemical bases

Front 19

proteins

Back 19

most organic compound in cells provides a cell structure actr as enzymes, pigments, toxiants, antibodies, hormones and transport mechanisms. serve as energy under starvation conditions