Ch. 2 The Chemistry Of Biology

Front 1

matter

Back 1

all tangible materials that occupy space and have mass

Front 2

atom

Back 2

tiny particle that cannot be subdivided into smaller substances without losing its properties

Front 3

protons

Back 3

positively charged subatomic particles

Front 4

neutrons

Back 4

neutral subatomic particles

Front 5

electrons

Back 5

negatively charged subatomic particles

Front 6

nucleus

Back 6

central core made of protons and neutrons

Front 7

atomic number (AN)

Back 7

number of protons an element has

Front 8

mass number (MN)

Back 8

the number of protons + neutrons

Front 9

isotopes

Back 9

variant forms of the same element that differ in the number of neutrons and thus have different mass numbers

Front 10

atomic mass or weight

Back 10

average mass numbers of all isotopic forms

Front 11

molecule

Back 11

distinct chemical substance that results from the combination of two or more atoms

Front 12

compounds

Back 12

contains two or more different elements

Front 13

molecular weight (MW)

Back 13

sum of all of the atomic masses of the atom the molecule contains

Front 14

chemical bonds

Back 14

created when two or more atoms share, donate or accept electrons

Front 15

valence

Back 15

capacity for making bonds determined by the number of electrons that an atom has to lose or share with other atoms during bond formation

Front 16

covalent bonds

Back 16

form between atoms with valences that suit them to sharing electrons instead of donating or receiving them

Front 17

polar

Back 17

unequal distribution of charges

Front 18

nonpolar

Back 18

electrically neutral molecule

Front 19

ionic bonds

Back 19

electrons are transferred completely from one atom to another and are not shared

Front 20

ionization

Back 20

creation of charged particles when the ionic bond is broken and the atoms dissociate into ions

Front 21

ions

Back 21

unattached charged particles

Front 22

cations

Back 22

positively charged ions

Front 23

anions

Back 23

negatively charged ions

Front 24

electrolytes

Back 24

substances that release ions when dissolved in water

Front 25

hydrogen bond

Back 25

weak electrostatic force that forms between a H covalently bonded to one molecule and an O or N

Front 26

van der Waals forces

Back 26

weak molecular interactions

Front 27

oxidation reduction reaction

Back 27

electrons are transferred from one atom or molecule to another

Front 28

reducing agent

Back 28

atom that can donate electrons to reduce another atom

Front 29

oxidizing agent

Back 29

atom that can receive extra electrons to oxidize another atom

Front 30

synthesis reaction

Back 30

reactants bond together in a manner that produces an entirely new molecule

A + B --> AB

Front 31

decomposition reactions

Back 31

bonds on a single reactant molecule are permanently broken to release two or more product molecules

Front 32

exchange reactions

Back 32

reactants trade portions between each other and release products that are combinations of the two

AB + XY --> <-- AY + XB

Front 33

catalysts

Back 33

substances that increase the rate of a reaction

Front 34

hydrated

Back 34

surrounded by a sphere of water molecules

Front 35

hydrohilic

Back 35

attract water

Front 36

hydrophobic

Back 36

repel water

Front 37

amphipathic

Back 37

have both hydrophilic and hydrophobic properties

Front 38

concentration

Back 38

the amount of solute dissolved in a certain amount of solvent

Front 39

acidic solution

Back 39

when one of its components (an acid) releases excess hydrogen ions

Front 40

basic (alkaline) solution

Back 40

when a component (a base) releases excess hydroxide ions

Front 41

pH

Back 41

graduated numerical scale ranging from 0 (most acidic) to 14 (most basic)

Front 42

neutrality

Back 42

pH 7, concentrations are exactly equal and neither predominates

Front 43

neutralization reactions

Back 43

give rise to water and other neutral by-products

Front 44

metabolism

Back 44

totality of chemical and physical processes occurring in the cell

Front 45

inorganic chemicals

Back 45

chemical that does not contain both carbon and hydrogen

Front 46

organic chemicals

Back 46

contains a basic framework of carbon bonded to hydrogens

Front 47

functional groups

Back 47

special molecular groups that help define the chemical class of certain groups and confer unique reactive properties on the whole molecule

Front 48

monomers

Back 48

repeating subunits of macromolecules

Front 49

polymers

Back 49

monomers bound into chains of various lengths

Front 50

carbohydrate

Back 50

backbone of carbon bound to two or more hydroxyl groups

Front 51

saccharide

Back 51

simple carbohydrate

Front 52

monosaccharide

Back 52

simple polyhydroxy aldehyde or ketone containing 3-7 carbons

Front 53

disaccharide

Back 53

combination of two monosaccharides

Front 54

polysaccharide

Back 54

polymer of five or more monosaccharides bond in linear or branched chain patterns

Front 55

glycosidic bonds

Back 55

link subunits of disaccharides and polysaccharides; carbons on adjacent sugar units are bonded to the same oxygen atom that links them

Front 56

dehydration synthesis

Back 56

process common to polymerization reactions that produces a water molecule

Front 57

cellulose

Back 57

forms cell walls in plants and some algae; long, fibrous polymer

Front 58

agar

Back 58

indispensable polysaccharide used as a solid culture media

Front 59

chitin

Back 59

polymer of glucosamine; major component of of cell walls of fungi

Front 60

peptidoglycan

Back 60

polysaccharides linked to peptide fragments; main source of structural support to bacterial cell wall

Front 61

glycocalyx

Back 61

outer surface composed of polysaccharides bound to proteins; functions in attachment to other cells or as site for receptors

Front 62

lipid

Back 62

substances not soluble in polar solvents, but will dissolve in nonpolar solvents

Front 63

triglycerides

Back 63

composed of single glycerol bound to 3 fatty acids

Front 64

glycerol

Back 64

3 carbon alcohol

Front 65

ester bond

Back 65

formed between OH group and COOH group between glycerol and fatty acids

Front 66

phospholipids

Back 66

major structural component of cell membranes; contain 2 fatty acids and a phosphate attached to the glycerol

Front 67

cholesterol

Back 67

steroid that reinforces the structure of the cell membrane in animal cells and cell wall deficient bacteria (mycoplasmas)

Front 68

proteins

Front 69

amino acids

Back 69

building blocks of protein; consist of a central carbon linked to an amino group, a carboxyl group, a hydrogen, and a variable R group

Front 70

peptide bond

Back 70

forms between amino group on one amino acid and the carboxyl group of another amino acid

Front 71

polypeptide

Back 71

contains more than 20 amino acids

Front 72

primary structure

Back 72

fundamental chain of amino acids

Front 73

secondary structure

Back 73

arises from hydrogen bonds between the C=O and N-H groups of peptide bonds; causes whole chain to coil and fold into alpha helix and beta-pleated sheets

Front 74

tertiary structure

Back 74

formed by additional hydrogen bonds between charged functional groups, van der Waals forces, and covalent disulfide bonds between cysteines

Front 75

quaternary structure

Back 75

two or more polypeptides interact to form a large, multiunit protein

Front 76

enzymes

Back 76

catalysts for chemical reactions in cells

Front 77

antibodies

Back 77

complex glycoproteins with specific regions of attachment for bacteria, viruses, and other microbes

Front 78

nucleotides

Back 78

make up nucleic acids; composed of a nitrogen base, a pentose sugar, and a phosphate

Front 79

purines

Back 79

adenine and guanine

Front 80

pyrimidines

Back 80

thymine, cytosine, and uracil

Front 81

ATP

Back 81

nucleotide containing adenine, ribose, and 3 phosphates; high-energy compound