Metabolism and Survival Flashcards
(75 cards)
1
Q
catabolic pathways=
A
break down of complex molecules to simpler ones (energy releasing)
2
Q
anabolic pathways=
A
biosynthesis of molecules from building blocks (energy requiring)
3
Q
Why are reaction rates higher in membranes?
A
they form surfaces and compartments that allow high concentrations, high surface area to volume ratio allows high concentrations
4
Q
Fluid mosaic model=
A
protein pores , pumps and enzymes embedded in phospholipid membranes
5
Q
Proteins embedded within membrane functions=
A
- Channel proteins- allow specific molecules to pass through membrane by passive transport
- Protein pumps- binds to specific molecules temp allowing them to cross membrane (active transport)
- Enzymes- catalyse
- Structural support- maintain shape
6
Q
How do enzymes lower activation energy?
A
- Bringing substarates to active site
- Orienting substrates correctly
- Removing products from active site (low affinity for active site)
7
Q
Induced fit=
A
active site is not rigid, is dynamic and flexible so alters it’s shape to fit substrate
8
Q
How do enzymes often act?
A
in groups or multi-enzyme complexes
9
Q
Rate of metabolism depends on
A
rate of enzyme activity
10
Q
Non-competitive inhibition=
A
the shape of the active site is altered by the
particle binding at allosteric site on the enzyme
11
Q
Competitive inhibition=
A
competes with substrate at active site
12
Q
Feedback inhibtion=
A
end product binds to allosteric site of first enzymes to alter activity
13
Q
Respiration=
A
convert energy stored in glucose to ATP that can be used by cells
14
Q
3 stages of respiration
A
- glycolysis
- citric acid cycle
- electron transport chain
15
Q
glycolysis occurs in
A
cytoplasm
16
Q
citric acid cycle occurs in
A
matrix of mitochondria
17
Q
et chain occurs in
A
cristae
18
Q
Main roles of ATP
A
- transfer of energy
2. phosphorylation of molecules
19
Q
Phosphorylation=
A
addition of pi to a molecule like ADP that leads to more gain of ATP
20
Q
What can fats and proteins be converted into?
A
intermediates of citric acid cycle and glycolysis
21
Q
What are other sugars converted to?
A
glucose or intermediates of glycolysis
22
Q
What breaks down into glucose?
A
start and glycogen
23
Q
What can metabolic rate be measured as?
A
- oxygen consumption per unit time (respirometer)
- carbon dioxide consumption per unit time
- energy production (as heat) per unit time (calorimeter)
24
Q
High metabolic rates require
A
efficient delivery of oxygen to cells
25
Best measure of fitness in humans=
maximum oxygen uptake
26
Incomplete double circulatory system
2 entries for blood, deoxygenated from body and oxygenated from lungs, mixing of blood- amphibians
27
Single circulatory system
blood flows in a single circuit, blood reoxygenated at the gills- fish
28
Double complete circulatory system
Closed loops for oxygenated and deoxygenated blood, efficient delivery of oxygen to cells- birds and mammals
29
Amphibian lungs
- gas exchange happens through mucosa in mouth and through the skin
- small lungs with alveoli can be used during rigorous activity
30
Reptile and mammal lungs
- branching tubes that end with alveoli, moist inner lining
| - bidirectional airflow and gas exchange over large surface area
31
Bird lungs
- unidirectional airflow
- gas exchange happens over small suface area in parabrochi but constant flow of oxygen-rich air is ensured due to air sacs = more efficient oxygen absorption
32
Deep diving animals adaptations:
lower heart rate when diving, more myoglobin (oxygen storing protein) in muscle tissue, divert blood to vital organs= decreases metabolic rate
33
High altitude training=
RBC count increases= temporary boost to fitness levels, increased risk of blood clots
34
homeostasis=
maintenance of a steady internal environment
35
conformers=
internal state varies with eextrnal state (same temp as environment)
36
regulators=
internal state does not vary with external state (within a range)
37
pros and cons of regulators=
pro- can exploit wide range of ecological niches, more adaptable to environmental change
con- high energy expenditure on homeostasis
38
pros and cons of conformers=
pros- low amount of engrgy needed for maintenance of body
| cons- can't exploit wide range of ecological niches, not adaptable to environmental change
39
osmoregulator=
able to maintain right internal water and salt concentration
40
thermoregulation role of hypothalamus, nerves and effectors
```
hypothalamus= receptor
nerves= carry signals to effectors
effectors= carry out action, can be capillaries, sweat glands, muscles
```
41
vasodialation=
opening of capillaries= increases heat loss by radiation and evaporation by sweat
42
vasocontriction=
narrowing of capillaries= reduces heat loss by radiation and evaporation by sweat
43
sweat gland role in thermoregulation
hot- releases more sweat which cools body as heat is required to evaporate it
cold- release less to reduce evaporation heat loss
44
hair role in thermoregulation
cold- erector muscles contract, pulling hair upright which traps layer of air that acts as an insulator
hot- relax
45
muscles role in thermoregulation
shiver if cold= generates heat in muscles
46
Predictive dormancy
organism enters a state before conditions change
47
Consequentive dormancy
organism enters a state as a result of changing conditions
48
Dormancy
period of reduced metabolic activity
49
Hibernation
sustained lowering of metabolism to survive low availability of food- bear
50
Aestivation
lowered metabolism to survive extreme drought or heat- snail
51
Daily torpor
daily decrease in metabolic rate- hummingbirds
52
Migration
relocating to a more suitable environment to avoid metabolic adversity
53
Innate influences on migration are
inborn responses to migration- route taken
54
Learned influences on migration are
modifications to innate- stop points in route
55
Techniques to study long distance migration
tagging, radio transmitters, satellite tracking
56
extremophiles
organisms that live under conditions which would prove lethal to almost any others
57
example of an extremophile
thermophyllic bacteria- live in hot springs or deep sea thermal vents, can generate ATP from inorganic
molecules.
58
culture conditions to eliminate effects of contaminating microorganisms:
- control of oxygen levels by aeration
- control of temperature in an incubator
- control of pH by buffers or addition of acid or alkali
59
compounds that can be added to growth media
vitamins and fatty acids
60
bacteria divide by
binary fission
61
generation time=
time taken for a cell to divide or a population to double
62
Phases of bacterial growth
lag phase= enzyme induced, adapting to surroundings, slow growth
log phase= exponential growth, optimal conditions
stationary phase= rate of death and new bacteria are equal, secondary metabolites are produced
death phase= lack of substrate and toxic accumulation of metabolites, #death > #new bacteria
63
How do secondary metabolites confer ecological advantage?
produces substances not associated with growth
64
How can wild strains of microorganisms be improved?
mutagenesis, selective breeding or recombinant DNA
65
mutagenesis=
artificially exposing microorganisms to mutagenic agents to produce new, improved strains.
66
How can some bacteria produce new strains?
```
transfer plasmids or pieces of chromosomal DNA to
each other (horizontal transfer), or take up DNA from their environment
```
67
How do fungi like yeast produce new phenotypes?
sexual reproduction
68
marker genes=
allow scientists to determine whether a cell has taken
| up the vector or not
69
restriction endonucleases=
enzymes that cut specific target sequences
| of DNA
70
role of ligase in recombinant DNA=
rejoins the backbone of DNA
71
regulatory sequences
control expression of the inserted gene as well
| as other genes found on the vector
72
recombinant DNA technology
ability to manipulate the genome of an organism by introducing new gene sequences.
73
restriction site=
allows the vector to be cut in a way which allows a
| fragment of DNA to be inserted into it
74
What does recombinant yeast cells prevent?
plant or animal recombinant DNA in bacteria may result in polypeptides that are folded incorrectly or lack post-translational modifications
75
How can you increase yield in recombinant DNA technology?
introduce genes that remove inhibitory controls or amplify specific metabolic steps in a pathway
