Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Building blocks of life > life at extremes > Flashcards

life at extremes Flashcards

1
Q

how are cells dynamic

A

not static
active
can respond to their environments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

define robustness

A

the ability of a cell to maintain performance and function in the face of internal and external disruptions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how does fever during infection help the mmune system?

A

increased white blood cell movement
increased proliferation of T cells/WBC
enhanced rate of phagocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what happens to cells at high tempertures eg above 37

A

they get stressed
enzymes cant work properly.denatured
proteins dont fold properly
membrane more fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the consequence of an ill-folded protein?

A

faulty protein
loss of regulatory component
loss of control of the protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what happens to membranes as they become too hot?

A

hard to control movement

too fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does the membrane do if it becomes too hot?

A

change the lipid composition to being fully saturated

cholestrol added

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what does a fully saturated lipid membrane mean>

A

single bonds only
most viscous
compact
less permeable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what does cholesterol do to membranes?

A

adds strength and stabilises the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how is the issue of proteins not folding properly fixed?

A

heat shock proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a heat shock proteins?

A

produced when the cell is exposed to elevated, sub-lethal temperatures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the function of a heat shock protein?

A

help proteins fold properly

they bind to proteins that are newly synthesied and hold them in place for binding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what issues are caused by low temperatures

A

slow enzyme reactions
rigid and viscous membranes
ice crystals making holes in membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how does the membrane respond to being too cold

A

unsaturate the lipids making them have double bonds
this makes the membrane more fluid
cholesterol is removed and the membrane made less stable and more fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the function of glycoproteins and glycolipids

A

protect the cell
stablise protein structures in ECM
buffer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how are glycolipids and gycoproteins produced?

A

carbohydrates are added to proteins in the RER
glycosidic bonds link these to the side chains of amino acids
flags the protein to be moved to membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how can ice crystals be bad?

A

kill the cell by punching holes in the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How do artic fish prevent ice crystals forming?

A

glycoproteins in blood arrange the formation of the crystals so they form along protein making them harmless to cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what’s special about the wood frog?

A

can freeze solid and thaw out multiple times and be fine

antifreeze glycopoteins and high gluose levels help them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how can bacteria survive extreme temperatures

A

proteins and metabolism in some mean they can be optimised for cold temps
their proteins are flexible and only work at the certain temperature ranges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is chitin

A

structural carbohydrate used with other substances to create a harder material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

whats wrong with low oxygen?

A

essential in ATP synthesis
low oxygen is toxic
death via necrosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what oxygen do cells like?

A

low oxygen

as you get further from blood vessels, nutrients and oxygen decrease anyway

24
Q

what is hypoxia

A

and environment low in oxygen
high altitude
aquatic

25
Q

when can hypoxia occur?

A

premature babies
poisoning
anaemia

26
Q

what is local hypoxia

A

ischaemiea strokes

cancer and vessels collapse

27
Q

how do cells sense hypoxia?

A

special oxygen sensing enzymes

28
Q

how do oxygen sensing enzymes work?

A

they activate a range of transcriptional factors
stop cell cycle after G1
stop things that arent essential
switch to anaerobic respiration

29
Q

what is angiogenesis?

A

making new blood vessels

30
Q

how does angiogenesis occur?

A

in response to hypoxia cells activate genes

cells are stimulated in vessles to branch off, proliferate and move towards hypoxic cells

31
Q

what causes the cells to proliferate in angiogenesis?

A

genes involved in growth factors such as VEGF and FGF

32
Q

what is VEGF?

A

vascular endothelial growth factor

33
Q

how do cancer cells exploit angiogenesis?

A

they are high demand cells and use energy quickly
they send out growth signals that act on nearby vessels
the vessels send off shoots towards the tumour in all directions and the tumour ends up with an extensive blood supply helping it grow

34
Q

what is quiescence?

A

state of reversible cell cycle arrest

35
Q

what happens in quiescence?

A

stay in G0 phase
starvation of the cell
low metabolic rates
non-essential things are shutdown

36
Q

what is irreversible cell cycle arrest called?

A

senescent

37
Q

what is autophagy

A

Self-eating

protective mechanism

38
Q

how does autophagy work?

A

cells form membrane vesicles called autophagosomes

to digest organelles and proteins with enzymes

39
Q

why is autophagy used?

A

efficient method to recycle building blocks in times of nutrient deprivation

40
Q

example of a small scale autophagy?

A

proteasome

41
Q

what does a proteasome do?

A

recycle individual proteins and amino acids for more protein synthesis

42
Q

examples of toxic environments for cells

A

raidation, UV light
free radicals and oxidative stress
toxins and posions

43
Q

how is a reactive oxygen species made

A

last step in transferring electrons to oxygen doesnt happen
creates highly reactive oxygen species
made in cells as side effect of normal metabolism

44
Q

what can reactive oxygen species do to cells?

A

react with biological molecules
chain reaction of macromolecules creating more radicals
modify proteins

45
Q

what effect can ROS have on proteins?

A

modify structure and function
crosslink or fragment them
modify nucleotides

46
Q

how can you prevent ROS damage?

A

antioxidants

47
Q

how do antioxidants prevent reactive oxygen species damage

A

react with them and neutralise them

48
Q

an example of natural antioxidant in the body

A

glutathione
found in the liver
donates electrons to ROS to make them more stable

49
Q

what is superoxide?

A

converts superoxide to hydrogen peroxide
then catlase converts that to water
line of defence to help

50
Q

whats a drug transporter?

A

transmembrane protien using ATP to transport drugs and substances across membranes

51
Q

the purpose of drug transporters?

A

stops exposure to chemicals
gets things out of cells before they cause damage
transports small dangerous chemicals they dont like

52
Q

what is the DNA damage response mechanism?

A

detection
cell cycle stops
repair initiated, genes turned on
if damage extensive cell undergoes apoptosis

53
Q

list some things damaging dna

A 
cellular metabolism
UV light
ionising radiation
chemical exposure
replication errors
54
Q

what is the integrated stress response?

A

series of mechanisms to protect the cell and fluctuations in the environment

55
Q

what are the cells defences?

A

antioxidants
DNA repair
apoptosis
ECM

Building blocks of life (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions