exam 2 Flashcards
1
Q
Passive transport
A
when molecules move across a membrane by diffusion
2
Q
Diffusion
A
the net movement of substances like ions and molecules from areas of higher to lower concentration
3
Q
Simple diffusion
A
molecules move directly through the lipid bilayer
4
Q
Facilitated diffusion
A
molecules move through a membrane transporter
5
Q
Active transport
A
the “uphill” movement of substances against a concentration gradient
6
Q
Active transport one
A
uses energy of ATP directly
7
Q
Active transport two
A
driven by an electrochemical gradient’s potential energy
8
Q
Chemical/concentration gradient
A
proton pump creates this, concentration of protons is higher on one side of the membrane
9
Q
Electrical gradient
A
side of membrane with more protons has higher positive charge than other side, protons move from areas of like charge to unlike
10
Q
Proton pump
A
a protein that moves protons across a membrane
11
Q
Phospholipid ends
A
phosphate head and fatty acid tail
12
Q
Bilayer
A
2 layers of lipids, heads on outside and tails on inside
13
Q
Cholesterol ends
A
hydrophilic hydroxyl region and hydrophobic 4 carbon ring region
14
Q
Fluidity
A
high temp decreases fluidity, longer tail decreases fluidity, fewer C=C bonds decreases fluidity
15
Q
membrane proteins
A
transporters, receptors, enzymes, anchors
16
Q
transporter proteins
A
move ions or molecules across membrane
17
Q
receptor proteins
A
allow the cell to receive signals from the environment
18
Q
enzymes
A
protein catalysts in biological systems, reduce the activation energy of a chemical reaction
19
Q
anchor proteins
A
attach to other proteins and help to maintain cell structure and shape
20
Q
integral membrane proteins
A
permanently associated with cell membranes and cannot be separated from the membrane without destroying the entire structure
21
Q
peripheral membrane proteins
A
temporarily associated with the lipid bilayer or with integral membrane proteins through weak noncovalent interactions
22
Q
transmembrane proteins
A
span the entire lipid bilayer, have 2 hydrophilic regions and 1 hydrophobic region
23
Q
fluid mosaic model
A
the lipid bilayer is a structure in which molecules move laterally (fluid) and its a mixture (mosaic) of different types of molecules such as lipids, proteins, and carbs
24
Q
osmosis
A
net movement of a solvent such as water across a selectively permeable membrane
25
osmotic pressure
the tendency of a solution to draw water in by osmosis, higher solute concentration = higher osmotic pressure
26
aquaporins
channel proteins that water moves through the cell by
27
channel proteins
provide an opening between the inside and outside of the cell through which certain molecules (depending on their shape and charge) can pass
28
carrier proteins
binds to and then transports specific molecules
29
contractile vacuoles
organelles that take up excess water from inside the cell and then, by contraction, expell it into the external environment
30
turgor pressure
force extended by water pressing against an object, builds as a result of water moving by osmosis into cells surrounded by cell walls
31
cytoskeleton
system of protein filaments that the shape of a cell depends on
32
phototrophs
organisms that capture energy from sunlight
33
types of phototrophs
plants, glucose
34
chemotrophs
organisms that derive their energy directly from chemical compounds
35
types of chemotrophs
animals
36
autotrophs
organisms that are able to convert carbon dioxide into glucose, self feeders
37
types of autotrophs
plants
38
heterotrophs
organisms that obtain their carbon from organic molecules synthesized by other organisms, other feeders
39
types of herterotrophs
animals
40
metabolism
the set of chemical reactions that convert molecules into other molecules and transfer energy in living organisms
41
catabolism
the set of chemical reactions that break down molecules into smaller units and produce ATP in the process
42
anabolism
the set of chemical reactions that build molecules from smaller units and require an input of energy (ATP)
43
kinetic energy
the energy of motion
44
examples of kinetic energy
a person running, a muscle contracting, light, electricity
45
potential energy
stored energy, possessed by immobile objects, is released by a change in an object's structure or position
46
examples of potential energy
an electrochemical gradient of molecules across a cell membrane, ball at the top of the stairs
47
chemical energy
potential energy held in the chemical bonds between pairs of atoms in a molecule
48
breaking covalent bond
energy required
49
forming covalent bond
energy released
50
examples of chemical energy
ATP
51
what does ATP stand for
adenosine triphosphate
52
what does ADP stand for
adenosine diphosphate
53
what does ATP do
drives muscle contraction, cell movement, membrane pumps
54
what is ATP made up of
core adenosine = base adenine, five carbon sugar ribose
55
first law of thermodynamics
the conservation of energy, states that the universe contains a constant amount of energy that is neither created nor destroyed
56
second law of thermodynamics
energy transformations always result in an increase in disorder in the universe, the degree of disorder is called entropy
57
thermal energy
a type of kinetic energy corresponding to the motion of molecules and results in a given temperature
58
entropy and catabolic reactions
increase
59
entropy and anabolic reactions
decrease (accompanied by a higher increase in surroundings)
60
chemical equilibrium
the rate of the forward reaction equals the rate of the reverse reaction, concentrations of reactants and products do not change
61
gibbs free energy
the amount of energy available to do work
62
exergonic
reactions with a negative delta G that release energy and proceed spontaneously
63
endergonic
reactions with a positive delta G that require an input of energy and are not spontaneous
64
delta G depends on what
the change in enthalpy and disorder
65
hydrolysis of ATP
exergonic reaction, water molecule is split into proton and hydroxyl group
66
transition state
intermediate between reactants and products, extremely unstable and has a large amount of free energy
67
activation energy
the energy input necessary to reach the transition state
68
substrate
reactant in chemical reaction catalyzed by an enzyme
69
enzyme-substrate
in the presence of an enzyme, a substrate forms this complex with it
70
enzyme-product
while still part of the complex, the substrate is converted to product
71
active site
where enzymes bind substrates to form an enzyme-substrate complex, transient covalent bonds/weak covalent interactions stabilize the transition state
72
lock and key
substrate fits in enzyme perfectly
73
induced fit
enzyme molds around substrate
74
cofactors
additional nonprotein molecules required by many enzymes to function
75
organic cofactors
diverse, some of the vitamins you obtain from foods you eat
76
enzyme activity is affected by what
temperature, pH, inhibitors, activators
77
inhibitors
decrease activity of enzymes
78
competitive inhibitors
compete with the substrate for the active site of an enzyme, increase Km and don't change Vmax
79
noncompetitive inhibitors
bind to sites other than the active site, don't change Km and decrease Vmax
80
activators
increase activity of enzymes
81
allosteric enzymes
enzymes that are regulated by molecules that bind at sites other than their active sites, play a key role in the regulation of metabolic pathways
82
negative feedback
maintains homeostasis, final product inhibits first step of reaction
83
cellular respiration
uses chemical energy stored in molecules such as carbs and lipids to produce ATP
84
cellular respiration formula
C6 H12 O6 + 6O2 ---> 6CO2 + 6H2O + energy
85
substrate level phosphorylation
an organic molecule transfers a phosphate group directly to ADP to make ATP, produces 12% of ATP in cellular respiration
86
oxidative phosphorylation
chemical energy of organic molecules is transferred to electron carriers, which carry electrons to the electron transport chain, which transfers electrons to a final acceptor, produces 88% of ATP in cellular respiration
87
oxidation
loss of electrons
88
reduction
gain of electrons
89
oxidized NA/FA
NAD+, FAD
90
reduced NA/FA
NADH, FADH2
91
glycolysis
glucose is partially broken down to produce pyruvate, energy is transferred to ATP and reduced electron carriers
92
pyruvate oxidation
pyruvate is oxidized to another molecule called acetyl-CoA, producing reduced electron carriers and releasing carbon dioxide
93
citric acid cycle
acetyl group is completely oxidized to carbon dioxide, energy is transferred to ATP and reduced electron carriers
94
phase one of glycolysis
prep phase, 2 ATP consumed
95
phase two of glycolysis
cleavage phase
96
phase three of glycolysis
payoff phase, 4 ATP and 2 NADH produced
97
where pyruvate oxidation occurs
the mitochondrial matrix
98
intermembrane space
the space between the inner and outer membranes
99
mitochondrial matrix
the space enclosed by the inner membrane
100
what does one glucose in glycolysis make
two pyruvate
101
what is oxidized in the citric acid cycle
the acetyl group of acetyl-CoA is oxidized to CO2
102
where does the citric acid cycle take place
mitochondrial matrix
103
input in citric acid cycle
two molecules of acetyl-CoA
104
output in citric acid cycle
two ATP, 6 NADH, 2 FADH2
105
why is the citric acid cycle a cycle
because the starting molecule (oxaloacetate) is regenerated in the end
106
energetic coupling
a spontaneous reaction drives a nonspontaneous, requires net delta G be negative and must share an intermediate
107
phosphate head
hydrophilic, polar, forms hydrogen bonds with water
108
fatty acid tail
hydrophobic, nonpolar
109
what is the final electron acceptor
oxygen
110
what drives the synthesis of ATP in oxidative phosphorylation
proton gradient
111
what makes up the ETC
four large protein complexes embedded in inner mitochondrial membrane
112
where do electrons donated by NADH go in the ETC
complex I
113
where do electrons donated by FADH2 go in the ETC
complex II
114
what does complex IV catalyze in the ETC
O2 + 4e- + 4H+ ---> 2H2O
115
what do the steps in the ETC protein complexes do
reduce next electron acceptor in chain, pump protons across membrane
116
proton gradient
electrochemical gradient that stores energy, has high proton concentration in intermembrane space and low in mitochondrial matrix
117
what generates the proton gradient
oxidation of NADH and FADH2
118
ATP synthase
converts the energy of the proton gradient into the energy of ATP
119
F0
forms the channel in the inner mitochondrial membrane through which protons flow
120
F1
catalytic unit that synthesizes ATP
121
how does F1 catalyze the synthesis of ATP from ADP and Pi
proton flow through F0 causes it to rotate, which causes F1 to rotate, causing conformational changes
122
chemiosmosis
protons move from an area of high concentration to low across a semi permeable membrane
123
1 NADH in oxidative phosphorylation makes
2.5 ATP
124
1 FADH2 in oxidative phosphorylation makes
1.5 ATP
125
cellular respiration total ATP produced
32 molecules
