Mitochondrial function and dysfunction Flashcards
functions of mitochondria
- oxidation of fat, protein and CHO for energy
- steroid hormones and neurotransmitter synthesis
- nucleotide synthesis
- calcium buffering
- growth and proliferation
- apoptosis and cell growth
anatomy of mitochondrion
- outer membrane
- intermembrane space
- innermembrane
- matrix
- cristae junction
- F0, F1 complexes
- DNA
- ribosomes
what is the mitochondria inner membrane permeable to
O2, CO2 and H2O
what is the mitochondria outer membrane permeable to
<5000 Da
3 stages of cellular respiration
- production of acetyl CoA (link reaction)
- oxidation of acetyl Coa
= TCA cycle - electron transport and chemiosmosis
how is acetyl CoA produced
from pyruvate in the link reaction
TCA Cycle
- Acetyl CoA (from link)
- citric acid
- isocitric acid
- alpha-ketoglutaric acid
- succinyl CoA
- Succinate
- Fumarate
- Malate
- oxaloacetate
- acetyl CoA
where in TCA is NADH produced
- isocitric acid -> alpha-ketoglutaric acid
- alpha-ketoglutaric acid -> succinyl CoA
- malate -> oxaloacetate
= 3 x NADH
Where in TCA is FADH2 produced
- succinate -> fumarate
= 1 x FADH2
Where is CO2 produced in the TCA cycle
- isocitric acid -> alpha-ketoglutaric acid
- alpha-ketoglutaric acid -> succinyl CoA
= 2 x CO2
where is ATP produced in the TCA cycle
- succinyl CoA -> succinate
= 1 x ATP
reduced NAD
NADH
Steps of ETC
- Complex I takes 2e- from NADH. Energy released is used to pump 4H+ across the membrane
- complex II takes 2e- from FADH2. No H+ is pumpd across the membrane
- Ubiquinone (Q) takes 2e- from complex I and II and transfers to complex III
- Complex III accepts these 2e- from Q. Energy released is used to pump H+ across the membrane
- Cyt C takes e- from complex III and transfers to complex IV
- Complex IV accepts e- from Cyt C
- cycle repeats and Complex IV accumulates 4e-
- 4e- used to reduce molecular oxygen to water
what transfers electrons from Complex I and II to complex III
ubiquinone (Q)
what does ubiquinone do in ETC
transfers e- from Complex I and II to complex III
Where does complex I take it 2e- from
NADH
Where does complex Ii take it 2e- from
FADH2
Where does complex III get its 2e- from
Ubiquinione, Q
what does Cyt C do
takes e- from complex III to complex IV
where does complex IV get its e- from
Cyt c, from complex IV
What happens when complex IV accumulates 4e-
4e- used to reduce molecular oxygen to water
which complexes pump H across membrane
I, III and IV
where to pumped protons go
enter ATPase to produce ATP via chemiosmosis
where is Q
inner mitochondrial membrane