Chapter 2; The Chemistry Of Life Flashcards
(186 cards)
1
Q
Biochemistry
A
study of the molecules that compose living organisms
2
Q
Element
A
simplest form of matter to have unique chemical properties
3
Q
Atomic Number
A
number of protons in the nucleus
4
Q
Trace Elements
A
element that does not account for more than 0.02%
5
Q
Minerals
A
inorganic elements extracted from the soil by plants and passed up the food chain to humans and other organisms
6
Q
Atoms
A
particles so small that are not visible to the human eye
7
Q
Protons
A
single positive charge
8
Q
Neutrons
A
no charge
9
Q
atomic mass
A
total number of protons and neutrons
10
Q
Electrons
A
tiny particles with a single negative charge and very low mass
11
Q
Electron levels
A
electrons swarm about the nucleus in concentric regions
12
Q
valence electrons
A
electrons on the outermost shell that determine the chemical bonding properties of an atom
13
Q
isotopes
A
each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei
14
Q
Deuterium
A
one proton and one neutron
15
Q
Tritium
A
one proton and two neutrons
16
Q
atomic weight (relative atomic mass)
A
mixture of isotopes
17
Q
radioisotopes
A
unstable isotopes
18
Q
radioactivity
A
process of decay
19
Q
Ionizing radiation
A
destroys molecules and produces dangerous free radicals and ions in human tissues
20
Q
mutagenetic
A
causing mutations in DNA
21
Q
carcinogenic
A
triggering cancer as a result of mutation
22
Q
alpha particles
A
consists of two protons and two neutrons
23
Q
beta particle
A
free electron
24
Q
gamma rays
A
very dangerous even when emitted by sources outside the body
25
physical half-life
the time required for 50% of its atoms to decay to a more stable state
26
biological half-life
time required for half of it to disappear from the body
27
ions
charged particles with unequal numbers of protons and electrons
28
background radiation
measure of the level of ionizing radiation present in the environment at a particular location
29
radon
a gas produced by the decay of uranium in the earth
30
anion
particle that gains electrons acquires a negative charge
31
cation
particle that loses electrons acquires a positive charge
32
Electrolytes
substances that ionize in water and form solutions capable of conducting electricity
33
Free radicals
chemical particles with an odd number of electrons
34
superoxide anion
when an additional electron is added, it becomes a free radical
35
antioxidant
a chemical that neutralizes free radicals
36
Superoxide dismutase (SOD)
enzyme that alternately catalyzes the dismutation of the superoxide radical into ordinary molecular oxygen and hydrogen peroxide
37
Molecules
chemical particles composed of two or more atoms united by a chemical bond
38
compounds
molecules composed of two or more elements
39
molecular formulae
represents molecules that identify their elements and show how many atoms of each are present
40
isomers
molecules with identical molecular formulae but different arrangements of their atoms
41
structural formulae
shows the location of each atom
42
molecular weight
sum of the atomic weights of its atoms
43
chemical bonds
a molecule that is held together and molecules are attached to one another by forces
44
ionic bond
relatively weak attraction between an anion and a cation
45
covalent bond
sharing of one or more pairs of electrons between nuclei
46
single covalent bond
sharing one electron pair
47
double covalent bond
sharing of two electron pairs
48
nonpolar covalent bond
covalent bond in which electrons are equally attracted to both nuclei
49
Polar covalent bond
covalent bond in which electrons are more attracted to one nucleus than to the other, resulting in slightly positive and negative regions in one molecule
50
Hydrogen bond
weak attraction between polarized molecules or between polarized regions of the same molecule
51
Van der Waals Force
weak, brief attraction due to random disturbances in the electron clouds of adjacent atoms (weakest bond)
52
mixture
consists of substances that are physically blended but not chemically combined
53
solvency
ability to dissolve other chemicals
54
universal solvent
water
55
hydrophilic
substances that dissolve in water
56
hydrophobic
substances that do not dissolve in water
57
hydration sphere
cluster of water molecules
58
adhesion
the tendency of one substance to cling to another
59
cohesion
tendency of molecules of the same substances to cling to each other
60
surface film
an elastic layer of water cohensed
61
chemical reactivity
ability to participate in chemical reactions
62
hydrolysis
ions that are incorporated into other molecules in the chemical reactions
63
thermal stability
helps to stabilize the internal temperature of the body
64
heat capacity
the amount of heat required to raise the temperature
65
calorie
base unit of heat
66
solution
mix of solutes and solvents
67
solute
particles of matter
68
solvent
more abundant substance
69
colloids
body are mixtures of protein and water
70
emulsion
a suspension of one liquid in another
71
acid (proton donor)
a molecule that releases a proton in water
72
base
proton accepter
73
pH
measure derived from the molarity of H+
74
neutral pH
7.0
75
acidic
pH below 7
76
basic (alkaline)
pH above 7
77
buffers
chemical solutions that resist changes in pH
78
weight per volume
weight of solute in a given volume of solution
79
percentage
weight of solute as a percentage of solution volume or volume of a liquid as a percentage of total solution volume
80
molarity
measure of the number of moles of solute per liter of solution
81
milliequivalents per liter
the unit of measure is used to express electrolyte to concentrations
82
energy
capacity to do work
83
work
to move something
84
potential energy
energy contained in an object because of its position or internal state but that is not doing work at the time
85
kinetic energy
energy of motion
86
chemical energy
potential energy stored in the bonds of molecules
87
heat
kinetic energy of molecular motion
88
electromagnetic energy
kinetic energy of moving "packets" of radiation called photons
89
electrical energy
both potential and kinetic energy
90
free energy
potential energy available in a system to do useful work
91
chemical reaction
process in which a covalent or ionic bond is formed or broken
92
chemical equation
shows the reactants on the left, the products on the right, and an arrow pointing from the reactants to the products
93
decomposition reactions
a large molecule breaks down into two or more smaller ones
94
synthesis reactions
two or more small molecules combine to form a larger one
95
exchange reactions
two molecules exchange atoms or groups of atoms
96
reversible reactions
can go in either direction under different circumstances
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law of mass action
they proceed from the reactants in greater quantity to the substances with the lesser quantity
98
equilibrium
the ratio of products to reactants is stable
99
concentration
reaction rate increases when the reactants are more concentrated
100
temperature
reaction rate increases as the temperature rises
101
catalysts
substances that temporarily bind to reactants, hold them in a favorable position to react with each other, and may change the shapes of reactants in ways that make them more likely to react
102
metabolism
all the chemical reactions in the body
103
catabolism
consists of energy-releasing decomposition reactions
104
exergonic reactions
energy-releasing reactions
105
Anabolism
consists of energy-storing synthesis reactions
106
endergonic reactions
reactions that require an Energy input
107
oxidixing agent (electron acceptor)
molecule that takes the electrons
108
reduction
a chemical reaction in which a molecule gains electrons and energy
109
reducing agent (electron donor)
a molecule that donates electrons to another
110
oxidation-reduction (redox) reactions
the oxidation of one molecule is always accompanied by the reduction of another
111
organic chemistry
the study of compounds of carbon
112
functional groups
small clusters of atoms that determine many of the properties of an organic molecule
113
macromolecules
gigantic organic molecules
114
polymerization
the joining of monomers to form a polymer
115
dehydration synthesis (condensation)
living cells achieve this by means of a reaction
116
dimer
the two monomers become joined by a covalent bond
117
carbohydrate
a hydrophilic organic molecule with the general formula
118
monosaccharides
the simplest carbohydrates
119
glucose
the "blood sugar" that provides energy to most of our cells
120
disaccharides
sugars composed of two monosacharides
121
sucrose
glucose + fructose
122
lactose
glucose + galactose
123
maltose
glucose + glucose
124
oligosaccharides
short chains of three or more monosaccharides
125
polysaccharides
long chains
126
glycogen
an energy-storage polysaccharide made by cells of the liver, muscles, brain, uterus, and vagina
127
starch
corresponding energy-storage polysaccharide of plants
128
cellulose
structural polysaccharide that gives strength to the cell walls of plants
129
glycoproteins
major component of mucus
130
proteoglycans
macromolecules in which the carbohydrate component is dominant and a peptide or protein forms a smaller component
131
lipids
a hydrophobic organic molecule
132
fatty acids
precursor of triglycerides, source of energy
133
triglycerides (neutral fats)
energy storage; thermal insulation; filling space; binding organs together; cushioning organs
134
phospholipids
major component of cell membranes; aid in fat digestion
135
eicosanoids
chemical messengers between cells
136
steroids
chemical messengers between cells
137
bile acids
steroids that aid in fat digestion and nutrient absorption
138
cholesterol
component of cell membranes; precursor of other steroids
139
fat-soluble vitamins (ADEK)
involved in a variety of functions including blood clotting, wound healing, vision, and calcium absorption
140
polyunsaturated fatty acids
those with multiple C=C bonds
141
prostaglandins
five of the carbon atoms are arranged in a ring
142
radical (R group)
the 20 amino acids used to make proteins are identical except for a third functional group
143
peptide
any molecule composed of two or more amino acids joined by peptide bonds
144
peptide bonds
formed by dehydration synthesis, joins the amino group of one amino acid to the carboxyl group of the next
145
oligopeptides
chains of fewer than 10 or 15 amino acids
146
polypeptides
chains larger than 15 amino acids
147
conformation
three-dimensional shape
148
primary structure
protein's sequence of amino acids, which is encoded in the genes
149
secondary structure
a coiled or folded shape held together by hydrogen bonds between the slightly negative -C=O group of one peptide bond and the slightly positive -NH group of another one some distance away
150
alpha helix
springlike shape
151
beta sheet
pleated, ribbonlike shape
152
tertiary structure
formed by the further bending and folding of proteins into various globular and fibrous shapes
153
alpha helix
spring-like shape
154
globular proteins
a compact tertiary structure well suited for proteins embedded in cell membranes and proteins that must move around freely
155
fibrous proteins
used for muscle contractions and providing strength to skin, hair, and tendons
156
Quaternary Structure
the association of two or more polypeptide chains by noncovalent forces
157
Denaturation
a more drastic conformational change in response to conditions
158
conjugated proteins
non-amino acid moiety
159
Keratin
a tough structural protein gives strength to nails, hair, and skin
160
collagen
durable protein
161
ligand
any hormone or molecule that reversibly binds to a protein
162
molecular motors (motor proteins)
special power that some proteins can change shape repeatedly
163
enzymes
proteins that function as biological catalysts
164
substrate
enzyme's action
165
amylase
digests starch
166
carbonic anhydrase
removes water
167
activation energy
the energy needed to get the reaction started
168
sucrase
an enzyme that breaks sucrose down to glucose and fructose
169
active site
a substrate molecule approaches a pocket on the enzyme surface
170
enzyme-substrate complex
the substrate binds to the enzyme
171
enzyme-substrate specificity
the substrate slightly changes the shape of the enzyme to create a better fit between the two
172
cofactor
about two-thirds of human enzymes require a nonprotein partner
173
coenzymes
organic cofactors usually derived from niacin, riboflavin, and other water soluble vitamins
174
aerobic respiration
uses energy from electrons to make ATP
175
metabolic pathway
a chain of reactions with each step usually catalyzed by a different enzyme
176
nucleotides
organic compounds with three principal components
177
nitrogenous base
a single or double carbon-nitrogen ring
178
adenine
double ring
179
ribose
sugar
180
adenosine triphosphate (ATP)
the body's most important energy-transfer molecule
181
adenosine triphosphatases (ATPases)
enzymes specialized to hydrolyze the third phosphate bond, producing ADP
182
guanosine triphosphate (GTP)
another nucleotide involved in energy transfers
183
cyclic adenosine monophosphate (cAMP)
a nucleotide formed by the removal of both the second and third phosphate groups from ATP
184
nucleic acids
polymers of nucleotides
185
deoxyribonucleic acid (DNA)
typically 100 million to 1 billion
186
ribonucleic acid (RNA)
70-10,000 nucleotides long, carry out those instructions and synthesize the proteins, assembling amino acids in the right order to produce each protein "described" by the DNA
