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Flashcards in Stress 2 Deck (12)
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1
Q

what happens in hyper-osmotic stress/ how does it effect the cell

A

happens if the cell goes from low to high osmotic stress - so water leaves the cell - cell shrinks - passively diffuses out

2
Q

what happens in hypo-osmotic stress/ how does it effect the cell

A

cell conditions go from salty to low osmolarity

water flows into the cell - strain on the cell wall - damages

3
Q

what is a cells response to changes in osmolarity

A

solutes synthesised/accumulated to help maintain balance

4
Q

name 4 solutes that may be accumulated for balance

A

glycerol
sugars
potassium
amino acids

5
Q

what other important molecule is synthesised and used widely for stress responses

A

trehalose

6
Q

improvement to osmotic stress is usually a …. trait

A

polygenic

controlled by many genes

7
Q

what is gTME

A

the random mutagenesis of multiple transcription factors at once, instead of manipulating many genes one after another
(TFs regulate genes)

8
Q

what is oxidative stress

A

inability to counteract or detoxify harmful effects of free radicals through neutralization by antioxidants

9
Q

what are free radicals

A

unstable molecules that damage/ oxidise cells

10
Q

what are ROS

A

Reactive Oxygen Species - chemically reactive chemical species containing oxygen eg peroxides

11
Q

how are ROS formed

A

as a natural bi-product of metabolism of oxygen generated in respiration
we have defence mechanisms, but can exceed antioxidant capacity of cells

12
Q

what is the stress response for oxidative stress

A

up-regulation of scavengers eg catalase

up regulation of enzymes that repair oxidative damage