Respiratory substrates Flashcards
1
Q
What is a respiratory substrate?
A
- organic molecules broken down to release energy for synthesis of ATP
2
Q
How does glycerol act as a respiratory substrate?
A
- converted to pyruvate before undergoing oxidative decarboxylation, producing an acetyl group that is picked up by CoA
3
Q
How do fatty acids in a triglyceride act as respiratory substrate?
A
- lead to formation as many as 50 acetyl group
- resulting in synthesis of up to 500 ATP molc
4
Q
How do different respiratory substrate compare in terms of energy release gram for gram?
A
- lips most
- glycerol
- carbs
- proteins rougly equivalent to carbs
5
Q
How do proteins act as respiratiory substrates?
A
- hydrolysed to amino acids
- then they are deaminated before they enter the respiratory pathway (usually pyruvate)
- this requires ATP, reducing the net production
6
Q
What is the repiratory quotient?
A
- calculated by dividing the volume of carbon dioxide released by the volum of oxygen taken in during respiration
- measured using respirometer
7
Q
Why do lipids result in the production of more ATP?
A
- contain greater proportion of C-H bonds
8
Q
WHat are the RQ values for common respiratory substrates
A
- carb - 1
- protein .9
- lipids .7
9
Q
Why do lipids have a low RQ value?
A
- require more oxygen to break them down and release relatively less carbon dioxide
10
Q
What is normal value for RQ?
A
- .8
- showing some lipids and carbs used (and probably proteins)
11
Q
what does a RQ value above one show?
A
anearobic respiration is occuring
