Respiratory Substances Flashcards
1
Q
What are respiratory substances?
A
Molecules that can be used as an energy source to allow the production of ATP from ADP and Pi
2
Q
What is the normal respiratory substance?
A
Glucose
3
Q
What else can be used a respiratory substance?
A
- Triglycerides
- Proteins
4
Q
Triglycerides as respiratory substances:
A
- Hydrolysed into glycerol and fatty acid
- Glycerol converted into pyruvate and enters respiration at the link reaction
- Fatty acid hydrolysed to form acetyl groups and enter respiration at Krebs cycle
- Three fatty acids in a single triglyceride can produce up to 50 acetyl groups that can form up to 500 ATP molecules
5
Q
Proteins as respiratory substances:
A
- Proteins digested to amino acids by proteases
- Amino acid deaminated
- Amino group converted into ammonia and then urea by ornithine cycle
- Remaining molecule converted to pyruvate, which enters respiration at the link reaction
6
Q
What are ketone bodies?
A
- Ketone bodies are molecules that contain a ketone group
- Produced when fatty acids are broken down for respiration during a long period of calorific restriction e.g. starvation
- Brain also uses ketone bodies to synthesise fatty acids
7
Q
What is a RQ value?
A
Unitless value that is the ratio of the volume of CO2 produced to the volume of O2 produced, expressed as a single value
8
Q
How to calculate a RQ value?
A
RQ= CO2 produced/ O2 consumed
9
Q
Why do lipids have a smaller RQ value than carbohydrates?
A
- Lipids contain more C-H bonds than glucose so can produce more NADH and FADH and more ATPs
- Therefore, they need less oxygen during respiration
