ch 2 Flashcards
(143 cards)
1
Q
chemistry
A
the science of the structure and interactions of matter
2
Q
matter
A
anything that occupies space and has mass
3
Q
mass
A
the amount of matter any any object, which does not change
4
Q
weight
A
the force of gravity acting on matter, does change
5
Q
atom
A
the smallest stable unit of matter
6
Q
element
A
matter composed of one kind of atom
a pure substance that cannot be split into simpler substances by ordinary chemical means
7
Q
4 major elements and %s
A
oxygen (65.0)
carbon (18.5)
hydrogen (9.5)
nitrogen (3.2)
8
Q
atomic number
A
the number of protons in the nucleus of an atom
9
Q
mass number
A
the sum of its protons and neutrons
10
Q
isotopes
A
atoms of an element that have different numbers of neutrons and therefore different mass numbers
11
Q
radioactive isotopes
A
unstable
nuclei decay (spontaneously change) into a stable configuration
12
Q
half-life
A
time required for half of the radioactive atoms in a sample of that isotope to decay into a more stable form
13
Q
dalton
A
standard unit for measuring the mass of atoms and their subatomic particles
14
Q
atomic mass
A
average mass of all of its naturally occurring isotopes
15
Q
ion
A
an atom that has a positive or negative charge because it has unequal numbers of protons and electrons
16
Q
ionization
A
the processof giving up or gaining electrons
17
Q
molecule
A
when two or more atoms share electrons
18
Q
compound
A
a substance that contains atoms of two or more different elements
19
Q
free radical
A
an atom or molecule with an unpaired electron in the outermost shell
- makes it unstable, highly reactive, and destructive to nearby molecules
20
Q
chemical bonds
A
the forces that hold together the atoms of a molecule of a compound
21
Q
valence shell
A
number of electrons in the outermost shell
22
Q
ionic bond
A
the force of attraction that holds together ions with opposite charges
23
Q
cation
A
positively charged ion
24
Q
anion
A
negatively charged ion
25
electrolyte
an ionic compound that breaks apart into positive and negative ions in solution
26
covalent bonds
strongest chemical bond
two or more atoms share electrons rather than gaining or losing them
27
nonpolar covalent bond
two atoms share the electrons equally
28
polar covalent bond
sharing of electrons between two atoms is unequal - the nucleus of one atom attracts the shared electrons more strongly than the nucleus of the other atom
29
electronegativity
the power to attract electrons to itself
30
hydrogen bond
forms when a hydrogen atoms with a partial positive charge attracts the partial negative charge of a neighboring electronegative atom
31
chemical reaction
occurs when new bonds form or old bonds break between atoms
32
reactants
the starting substances
33
products
the ending substances
34
irreversible reactions
proceed in only one direction, from reactants to products
35
reversible reaction
the products can revert to the original reactants
36
chemical equilibrium
the rate of the forward reaction is equal to the rate of the reverse reaction
37
law of mass action
the relationship between the net direction of a reversible reaction and the concentrations of the reactants and products
38
inorganic compounds
usually lack carbon and are structurally simple
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organic compounds
always contain carbon, usually hydrogen, and always have covalent bonds
40
water
the most important and abundant inorganic compound in all living systems
41
solution
solvent dissolves another substance called the solute
42
hydrophilic
water loving
dissolve easily in water
solutes that are charged or contain polar covalent bonds
43
hydrophobic
water fearing
not very water soluble
molecules that contain mainly nonpolar covalent bonds
44
hydrophobic interaction
when nonpolar molecules are present in an aqueous environment they aggregate to minimize their exposure to water
45
mixture
a combo of elements or compounds that are physically blended together but not bound by chemical bonds
46
colloid
homogenous noncrystalline substance consisting of large molecules of one substance dispersed through a second substance
47
suspension
suspended material may mix well with the liquid or suspending medium for some time, but eventually will settle out
48
3 ways to express concentration of a solution
molarity
equivalents
mass per volume
49
molarity
the number of moles of solute per liter of solution
(mol/L) or (M)
50
mole
the amount of any substance that has a mass in grams equal to the sum of the atomic masses of all of its atoms
51
equivalent
one mole of positive or negative changes (Eq/L)
52
mass per volume
indicates the mass of a solute found in a given volume of solution (g/L)
53
dissociate
separate into ions and become surrounded by water molecules
54
acid
a substance that dissociate into one or more hydrogen ions and one or more anions
a proton donor
55
hydrogen ion
a single proton with one positive charge
56
base
removes H+ from a solution
a proton acceptor
many dissociate into one or more OH- ions and one or more cations
57
salt, when dissolved in water, dissociate into
cations and anions, neither of which is H+ or OH-
58
pH
the negative logarithm of the hydrogen ion concentration in moles per liter
59
buffer systems
convert strong acids or bases into weak acids or bases
60
buffers
the chemical compounds that can convert strong acids or bases into weak ones
61
how do buffers work
remove or add protons
62
carbonic acid-bicarbonate buffer system
can compensate for either an excess or shortage of H+
carbonic acid can act as a weak base (when there is a shortage of H+)
bicarbonate ion can act as a weak base (when there is an excess of H+)
63
functional groups
specific arrangement of atoms that confers characteristic chemical properties on the organic molecule attached to it
64
macromolecules
very large molecules that are a combination of small organic molecules
usually polymers
65
polymers
a large molecule formed by the covalent bonding of monomers
66
monomer
identical or similar small building-block molecules
67
dehydration synthesis
the reaction that joins two monomers
68
hydrolysis
reverse of dehydration synthesis
polymers are broken down into monomers by the addition of water molecules
69
carbohydrates
large and diverse group of organic compounds that have several functions
70
three major groups of carbohydrates
monosaccharides
disaccharides
polysaccharides
71
monosaccharides
monomers of carbohydrates
contain three to seven carbon atoms
72
disaccharides
a molecule formed from the combination of two monosaccharides by dehydration synthesis
73
polysaccharide
contains hundreds to thousands of monosaccharides joined through dehydration synthesis reactions
74
glycogen
main polysaccharide in the human body
made entirely of glucose monomers linked to one another in branching chains
- stored form of carbs in animals
75
starches
polysaccharides formed from glucose by plants
- stored form of carbs in plants
76
cellulose
polysaccharide formed from glucose by plants that cannot be digested by humans but provides bulk to help eliminate feces
- part of cell wall
77
lipid
organic compound that contains carbon, hydrogen, and oxygen
most are insoluble in polar solvents
78
lipoproteins
lipid/protein complex that are more soluble in blood plasma
79
5 types of lipids
fatty acids
triglycerides
phospholipids
steroids
eicosanoids
80
fatty acid composisiton
simplest lipid
consist of a carboxyl group and a hydrocarbon chain
can be either saturated or unsaturated
81
fatty acid functions
- used to synthesize triglycerides and phospholipids
- can be broken down to generate ATP
82
saturated fatty acid
contains only single covalent bonds between the carbon atoms of the hydrocarbon chain
83
unsaturated fatty acids
contains one or more double covalent bonds between the carbon atoms of the hydrocarbon chain
84
triglycerides/triacylglycerols composition
consist of two types of building blocks: a single glycerol molecule and three fatty acid molecules
- can be solid or liquid at room temp
- most plentiful lipids in your body and diet
85
triglycerides functions
protection, insulation, energy storage
86
function of a three-carbon glycerol
forms the backbone of a triglyceride
87
fat
a triglyceride that is solid at room temp
fatty acids are mostly saturated
88
saturated fat
fat the mainly consists of saturated fatty acids
89
oil
a triglyceride that is liquid a room temp
fatty acids are mostly unsaturated
90
monounsaturated fats
contain triglycerides that consist mostly of monounsaturated fatty acids
91
polyunsaturated fats
contain triglycerides that consist mostly of polyunsaturated fatty acids
92
phospholipids composition
have a glycerol backbone and two fatty acid chains attached to the first two carbons. in the third position, a phosphate group links a small charged group that usually contains nitrogen to the backbone
- amphipathic
93
phospholipid function
major lipid component of cell membranes
94
amphipathic
molecules that have both polar and nonpolar parts
95
steroid composisiton
lipids that contain four interconnected hydrocarbon rings
96
cholesterol function
minor component of all animal cell membranes; precursor of bile salts, vitamin D, and steroid hormones
97
bile salts function
needed for digestion and absorption of dietary lipids
98
vitamin D function
helps regulate calcium level in the body; needed for bone growth and repair
99
adrenocortical hormones function
help regulate metabolism, resistance to stress, and salt and water balance
100
sex hormones function
stimulate reproductive functions and sexual characteristics
101
eicosanoids structure
lipids derived from a 20-carbon fatty acid called arachidonic acid
102
three principal subclasses of eicosanoids
prostaglandins
thromboxanes
leukotrienes
103
prostaglandins function
modify responses to hormones, contribute to the inflammatory response, and dilate airways to the lungs
104
thromboxanes function
constrict blood vessels and promote platelet actiavtion
105
leukotrienes function
participate in allergic and inflammatory response
106
proteins
large molecules that contain carbon, hydrogen, oxygen, and nitrogen
107
6 types of proteins
structural
regulatory
contractile
immunological
transport
catalytic
108
function and example of structural proteins
form structural framework of various parts of the body
ex. collagen in bone and other connective tissues
109
function and example of regulatory proteins
hormones that regulate various physiological processes, control growth and development; as neurotransmitters, mediate responses of the nervous system
ex. insulin regulates blood glucose levels, substance P mediates sensation of pain in the nervous system
110
function and example of contractile proteins
allow shortening of muscle cells, which produces movement
ex. myosin and actin
111
function and example of immunological proteins
aid responses that protect body against foreign substances and invading pathogens
ex. antibodies and interleukins
112
function and example of transport proteins
carry vital substances throughout the body or across a membrane
ex. hemoglobin transports most oxygen and some carbon dioxide in the blood
113
function and example of catalytic proteins
act as enzymes that regulate biochemical reactions
ex. salivary amylase
114
amino acids
monomers of proteins
contain (H), (-NH2), (-COOH), (R)
three major categories
- nonpolar
- polar uncharged
- polar charged
115
peptide bond
the covalent bond joining each pair of amino acids
(btw carbon of carboxyl group and nitrogen of amino group)
116
dipeptide
two amino acids
117
tripeptide
addition of an amino acid to a dipeptide
118
peptide
4-9 amino acids
119
polypeptide
10+ amino acids
120
primary structure
unique sequence of amino acids that are linked by covalent peptide bonds to form a polypeptide chain
121
secondary structure
repeated twisting or folding of neighboring amino acids in the polypeptide chain
- alpha helixes
- beta pleated sheets
122
tertiary structure
3D shape of a polypeptide chain
123
quaternary structure
arrangement of individual polypeptide chains relative to one another in proteins that contain more than one polypeptide chain
124
denaturation
the process of a protein unraveling or losing its characteristic shape and becomes nonfunctional
125
ligand
any molecule or ion that binds to a particular site on a protein through weak, noncovalent interactions
126
binding site
region of the protein where the ligand binds
127
4 properties of ligand-protein binding
specificity
affinity
saturation
competition
128
specificity
only one substance, or a small group of structurally related substances can bind to a given binding site on a protein
129
affinity
the strength with which a ligand binds to a protein
130
2 factors determining affinity
- the degree of shape complementarity
- strength of the noncovalent interactions
131
saturation
the degree to which the binding sites of a population of protein molecules are occupied by ligand
132
2 factors percent saturation of binding sites depend on
- the concentration of ligand
- the affinity of the binding sites for the ligand
133
competition
if ligands are so similar in structure they can bind to the same site on a protein which results in competition for binding
134
modulator
a chemical that binds to a protein and either alters the ligand's binding ability or changes the functional activity or the protein
135
covalent modulator
chemical that binds to a protein by covalent bonding which causes conformational change affecting its affinity to bind to the ligand
136
nucleic acids
huge organic molecules that contain carbon, hydrogen, oxygen, nitrogen, and phosphorus
137
gene
a segment of a DNA molecule that determine the traits we inherit and regulate most of the activities that take place in body cells throughout our lives
138
DNA vs RNA
DNA forms the inherited genetic material inside each human cell
RNA relays instructions from the genes to guide each cell's synthesis of proteins from amino acids
139
nucleotides
nucleic acid chains of repeating monomers
140
3 parts of nucleotides
a nitrogenous base
a pentose sugar
a phosphate group
141
nitrogenous base
a nitrogen containing molecule arranged in a single or double ring
142
pentose sugar
a five-carbon sugar that attaches to each nitrogenous base
143
phosphate group
alternates with pentose sugars to form the backbone of a DNA or RNA strand
