prelim 1 Flashcards
(120 cards)
1
Q
four main classes
A
carbohydrates, lipids, proteins, and nucleic acids
2
Q
polymer
A
long molecule consisting of many similar or identical building blocks linked by covalent bonds
3
Q
monomer
A
building block of polymer
4
Q
dehydration reaction
A
molecules are covalently bonded together through loss of water
5
Q
hydrolysis
A
bond broken by addition of water
6
Q
key sugar factors
A
carbonyl group, and multiple hydroxyl groups
7
Q
aldose sugar
A
carbonyl group at end of carbon skeleton
8
Q
ketose sugar
A
carbonyl group within carbon skeleton
9
Q
glycosidic reaction
A
a covalent bond formed between two monosaccharides by a dehydration reaction
10
Q
starch
A
used for storage in plants
11
Q
glycogen
A
animal storage
12
Q
cellulose
A
plant cell walls
13
Q
chitin
A
used in exoskeletons
14
Q
lipids
A
mix poorly with water, contain fats, phospholipids, and steroids
15
Q
fats are made of
A
three fatty acids and one glycerol molecule
16
Q
saturated fatty acids
A
packed closely, solid
straight chains
animal fats
17
Q
unsaturated fatty acids
A
packed loosely, liquid
kinked chains
plant fats
18
Q
phospholipid
A
glycerol and two fatty acids and phosphate group, non-polar hydrophobic chain, polar hydrophilic head
19
Q
steriods
A
lipid with four carbons
20
Q
protein functions
A
help with chemical reactions, protect, transport, store, respond, support, move
21
Q
polypeptide
A
polymer of amino acids
22
Q
protein is made of
A
made up of polypeptides
23
Q
phospholipids are known as
A
amphipathic, hydrophobic and hydrophilic
24
Q
membrane viscosity is increased by
A
saturated hydrocarbon tails, no kinks
25
phospholipids can move
laterally but dont readily flip
26
how do they measure membrane fluidity
Fluorescence recovery after photobleaching (FRAP)
protein tagged with fluorescence, area bleached with laser, bleached area only regains fluorescence by diffusion of unbleached proteins
27
why cant proteins readily diffuse within bilayer
some are anchored to carbo chains
28
which membranes are more fluid, those rich in unsaturated or saturated fatty acids
membranes rich
in unsaturated fatty acids are more fluid than those
rich in saturated fatty acids
(unsaturated have kinks so not tightly packed)
29
how does cholesterol affect membrane fluidity at different temps
```
At warm temperatures (such as 37°C),
cholesterol restrains movement of
phospholipids. At cool
temperatures, it maintains fluidity by
preventing tight packing.
```
30
peripheral proteins
bound by charges, on outside
31
what type of proteins can not be transmembrane
proteins with high surface charge
32
Six major functions of membrane proteins
```
Transport
• Enzymatic activity
• Signal transduction
• Cell-cell recognition
• Intercellular joining
• Attachment to the cytoskeleton and
extracellular matrix (ECM)
```
33
what molecules easily pass through membrane
nonpolar hydrophobic, ions and polar do not
34
tonicity
is the ability of a surrounding solution to cause a cell to gain or lose water
35
how do plant cells tonicity differ
plant cells are normally swollen (turgid)
so hypotonic is turgid
isotonic is flaccid
hypertonic is plasmolyzed
36
Facilitated diffusion
when transport proteins speed the passive movement of
| molecules across the plasma membrane
37
Example of facilitated diffusion
aquaporins facilitate movement of water
38
most active transport is modeled by
alternating access
39
Membrane potential
is the voltage difference across a membrane
40
what two forces drive the electrochemical gradient of diffusion of ions across membrane
A chemical force (the ion’s concentration gradient)
| An electrical force (the effect of the membrane potential on the ion’s movement)
41
The main electrogenic pump of plants, fungi, and bacteria is
proton pump
42
co-transport
when active transport of a solute indirectly drives
| transport of other substances, secondary active transport
43
Large molecules, such as polysaccharides and proteins, can cross the membrane via
vesicles
44
flipping a lipid
the phospholipid compositions differ between the outer and inner leaflets of the plasma and
organellar membranesFlip bases use energy of ATP, bind it and flip it from one side to the other
45
free energy, activation energy
initial energy needed to start a chemical reaction
46
Enzymes speed up metabolic reactions by
lowering energy barriers
| activation energy lowered, but difference in free energy is unaffected by enzymes
47
How might substrate binding lower E
Orienting substrates correctly
Straining substrate bonds
Providing a favorable microenvironment
Covalently bonding to the substrate
48
competitive inhibitors
bind to the active site of an enzyme, competing with the substrate
49
noncompetitive inhibitors
bind to another part of an enzyme, causing the enzyme to change
shape and making the active site less effective
50
Allosteric regulation
when a regulatory molecule binds to a protein at one site and
affects the protein’s function at another site
Allosteric regulation may either inhibit or stimulate an enzyme’s activity
51
feedback inhibition
the end product of a metabolic pathway reduces flow through the pathway
52
gibbs free energy equation
delta G = delta H - T deltaS
53
when are processes spontaneous
negative delta G
| spontaneous processes decrease systems free energy
54
what type of processes can be harnessed to do work
spontaneous
55
negative G, positive G, minimum G
negative means can proceed forward, positive means can go backwards (assuming no energy inout)
minimum is equilibrium so no net
56
exergonic reactions
free energy larger in reactants than products
| releases energy
57
endergonic reactions
free energy larger in products, consumes energy
58
energy
| coupling,
use of an exergonic process to drive an
endergonic one
mediated by ATP
59
Catabolic pathways
yield energy by oxidizing organic compounds
| release energy by breaking down
60
anabolic pathways
chemical reactions in which simpler substances are combined to
form more complex molecules; usually requires energy
61
oxidation-reduction
| reactions, or redox reactions
Chemical reactions that transfer electrons between reactants
62
oxidation
a substance loses electrons, or is oxidized
63
reduction
a substance gains electrons, or is reduced (the amount of positive charge
is reduced)
64
electron donor is called the
reducing agent
65
electron acceptor is called the
oxidizing agent
66
during cellular respiration what is oxidized and what is reduced
glucose is oxidized and oxygen is reduced
67
cellular respiration
Glycolysis
Pyruvate oxidation
Tricarboxylic acid cycle (aka TCA cycle or citric acid cycle)
Oxidative phosphorylation
68
Glycolysis
breaks down glucose into two molecules of pyruvate
| uses 2NAD+ and 2 ADP turns into 2 NADH and ATP
69
Pyruvate oxidation
oxidizes pyruvate to two acetyl-CoA + 2 CO2
| uses pyruvate and NAD+
70
TCA cycle
– completes the breakdown of glucose
uses water and 3 NAD+
makes CO2, 3NADH and FADH2
71
Oxidative phosphorylation
accounts for most of the ATP synthesis
| uses NADH and ADP
72
Pyruvate kinase deficiency
means less ATP production (PK part of the energy payoff phase)
so less work can be done
RBC shrivels
73
The equation linking the change in
E as electrons are transferred to
free energy:
```
delta G = -nF deltaE
n = number of electrons
F = Faraday constant (charge of
1 mol of electrons)
E = electrical potential
```
74
electron transport chain
H+ pumped out, NAD turns into NAD+, same with FADH, then water is made by H+ pump, when H+ comes back in, ATP made
75
Chemiosmosis
the movement
of ions across a semipermeable
membrane down their concentration gradient.
76
delta G = -nF deltaE means that during the transfer of electrons from food (reducing agent) to
O2
(oxidizing agent) work can be done if the E is of sufficient size. What work is
actually done by the redox components of the aerobic respiratory chain?
Generating a protonmotive force.
77
Lactic acid fermentation
```
make
NAD+ in which pyruvate
is the electron acceptor
and lactate is the product. No
CO2
is produced. The only ATP
produced is that made
during glycolysis by substrate
level phosphorylation. 1 and
2 are NADH producing
```
78
photosynthesis light reactions
The light reactions (in plants occurs in the thylakoids)
• Split H2O
• Release O2
• Reduce the electron acceptor NADP+
to NADPH
• Generate ATP from ADP by photophosphorylation
79
photosyntheisis
light reactions in thylakoid take in water, produce O2, make ATP and NADH
calvin cycle takes in ATP CO2 and NADH, makes sugar and gives NADP+ and ADP back to light reaction
80
Photosynthesis is a redox process in which
H2O is oxidized and CO2
is
reduced
Photosynthesis is an endergonic process; the energy boost is provided by light
81
ROYGBIV
| wavelength and energy
From R to V, decrease wavelength, increase energy
82
Carotenoids
function in photoprotection;
they absorb excessive light that would
damage chlorophyll
83
Energy transfer between molecules does not depend upon transfer of light or electrons but is
due to
donor energy transfer that requires direct interaction between the molecules
84
how photosystems work
photon goes into light harvesting complex, transfer energy, ends up at chloryphyll where boosts e- to electron acceptor in reaction center
85
During the light reactions, there are two possible routes for electron flow:
cyclic and linear
86
linear electron flow
primary pathway
e- come from water, light goes from pigment molecules and and propels e-, e- goes down transport chain to make ATP, e- goes into photosystem one with more light and makes NADPH
87
reaction centers cause
a charge separation
88
cyclic photosynthesis
one photosystem, no terminal e- acceptor continuous cycle
89
ATP synthesis during photosynthesis, as in respiration,
| relies
a proton gradient generated by electron flow
90
calvin cycle has three phases
carbon fixation
reduction
regeneration of CO2 acceptor (Rubp)
91
Calvin cycle process
3CO2 come in to rubisco (carbon fixation), uses 6ATP, uses 6 NADPH (reduction), makes 1 G3P
3ATP used to make 3 RuBP (regeneration)
92
temperature
a measure of the speed of the
| random motions of the atoms or molecules
93
heat
the total energy that a substance possesses
by virtue of the sum of random motions of its
atoms or molecules
94
Q10
quotient describing the sensitivity of a process to
| temperature in increments of 10
95
Q10=1, 2, or 3
1) rate of activity at 1, line,
2) rate of activity doubled
3) rate of activity tripled
96
ectotherms
temperature mostly regulated through environment
97
endotherms
mostly metabolic temp regulation
98
homeotherms
thermoregulation endotherms, birds, mammals,
99
non-regulating endotherms
naked mole rat, don’t regulate temp but heat comes from metabolic
100
poikiloterms
non regulating ectotherms, fish, bugs, heat comes from environment, dont regulate
101
thermoregulating ectoterms
behavioral thermoregulators
102
heterotherms
bats and hummingbirds, generate heat from metabolic but don’t always regulate temp, ex: bats they regulate during night but don’t regulate during day
103
H metabolism
always positive
| metabolism, muscular contraction
104
H radiative
gained or lostAll objects warmer than absolute zero (-273°C) emit radiation and lose energy
105
in radiation energy is lost or gained as
infrared electromagnetic waves
106
radiation depends on
The difference in temperature of the two surfaces
• The surface area of the objects (huge for small animals)
• And the color (the emissivity of the surfaces)
107
h conduction
gained or lost,direct transfer of kinetic energy of molecular motion and requires physical
contact of the object with either a solid, a liquid or a gas
108
conduction depends on
The difference in temperature of the two surfaces
• The area of contact
• Thermal conductivity (how well the surfaces conduct heat)
109
h convection
gained or lost,• Convection is a transfer of heat by mass flow within a fluid medium, such as air of water. in most cases convective cooling organism loses heat
110
convection depends on
Surface area of contact
• temperature difference between the object and the medium
• and rate of flow of the medium
111
h evaporation
always negative The change in phase from liquid to gas requires energy (vaporization heat). This energy is
removed from the object which the liquid leaves.
112
evaporation depends on
the ambient temperature at which the phase change takes place
• the volume of water evaporated
• the humidity of the ambient air
113
which factors are affected by volume and which by surface
metabolism- volume
| radiation, conduction, convection, and evaporation - surface
114
Kleiber’s law
Metabolic rate is proportional to body mass smaller animals have higher metabolic rates per gram than larger animals
115
Gigantothermy
Animal is so big that surface area-to-volume ratio is really small
Thus, once animal gets hot, it doesn’t lose heat fast and becomes essentially “endothermic”
116
isolation strategy
animals may evolutionary modify conductivity, distance to vital organs and adaptations that help reduce heat loss
117
Regional heterothermy
different regions of the body have different temperatures. This allows
to keep the core temperature more stable
118
countercurrent
| exchange
transfer heat between fluids flowing in opposite directions
| and thereby reduce heat loss
119
Benefits and costs of being an homeothermic endotherm
Benefits:
Greater independence from external thermal conditions
More flexibility in exploiting different habitats
Activity levels can be kept higher – biochemistry, foraging, escape
costs:
Energetically expensive, especially in colder habitats where Ta < Tb
Regulatory machinery, e.g., sensors, receptors, hormones, effectors
120
Uncoupling of oxidative phosphorylation in the mitochondria
generates heat,Thyroid hormone and the sympathetic nervous system induce thermogenesis. thermogenin uncouples electron transport and ATP formation
Protons leak back across inner mitochondrial membrane through thermogenin channel instead of shuttling
through ATP synthase => heat but no work
