cell biology 6 Flashcards
1
Q
describe mitochondrial fission
A
- Dyamin-1 exists as dimers in the cytosol
- GTP binding —> oligomeric structures form, interact with outer membrane adaptor proteins
- GTP- dyamin spiral forms —> constriction
- GTP-hydrolysis —> fission
2
Q
what does mitochondria fusion require
A
GDP and H+ gradient across the inner membrane
3
Q
what does the inner membrane dyamin related proteins form in mitochondrial fusion
A
oligomeric tethering complex
4
Q
how is outer membrane GTPase oligomeristation used in mitochondria fusion
A
- outer membrane fusion
5
Q
what does mitochondrial fusion ensure
A
- even distribution of mtDNA and reduce damaged DNA accumulation
6
Q
What does ATP synthase do
A
- uses the H+ gradient across the inner membrane
- membrane-embedded C subunits bind H+
- H+ transported down a concentration gradient
- H+ rides a full cycle before released
- rotation drives ATP production
7
Q
what is apoptosis
A
- cell death - programmed
- cell shrink, cytoskeleton collapse, nuclear envelope disassembles
- chromatin condenses and breaks up
8
Q
what is necrosis
A
- cell death due to acute insult
- cells swell and burst, spilling their contents and elicit an inflammatory response
9
Q
what is necropotosis
A
cell death due to signal from neighbouring cells
10
Q
why do cells regulate cell death
A
- early development to eliminate unwanted cells
- maintain cell populations in tissue
- wound healing
- immune reaction to remove damaged cells
- prevent cancer
