Component 1.3 - Anaerobic Respiration Flashcards
How is anaerobic different to aerobic respiration?
Without oxygen reduced NAD and FAD cannot be reoxidised and no NAD is regenerated so krebs and the link reaction can’t take place and electron transport chain cannot function.
What happens during anaerobic respiration in animals?
After glycolysis (forms ATP and reduced NAD)
1) Pyruvate is the hydrogen acceptor and is converted to lactate.
2) This regenerates NAD
Excess pyruvate can be converted to lactate in aerobic conditions
What happens during aerobic respiration in micro-organisms?
After glycolysis (forming ATP and reduced NAD)
1) Pyruvate is converted to co2 and ethanal
2) Ethanal is reduced to ethanol (addition of hydrogen)
3) NAD is regenerated in alcoholic fermentation
What is the difference between anaerobic respiration in animals and micro-organisms?
If oxygen becomes available the lactate can be respired to co2 and water (aerobic respiration) releasing energy.
In microorganisms even if oxygen becomes available ethanol is not broken down.
How much ATP is formed in anaerobic respiration?
2 molecules of ATP are formed in glycolysis and that is it because there is no ATP synthetase associated with the electron transport system.
How is reduced NAD formed in anaerobic respiration?
The 2H released in the conversion of glucose to Pyruvate reduces NAD and they are given up again in the formation of ethanol/lactate forming NAD meaning that glycolysis can continue.
How does glycerol feed into the Krebs cycle?
Glycerol is converted to a 3-carbon sugar (triose phosphate) which is an intermediate in glycolysis
This finishes glycolysis, goes through the link reaction and into the Krebs cycle.
How do fatty acids enter the Krebs cycle?
1) Fatty acid chains are split into 2C acetate fragments and enters the Krebs cycle as AcCoA
Why are fats not used for respiration?
More carbon atoms so more carbon dioxide produced. Limited blood supply to muscles meaning they wouldn’t be able to move co2 quick enough.
Why do tissues with a rich blood supply respire fat?
More hydrogen atoms, so more NAD is reduced so more ATP is produced to be readily transported around the body.
How do proteins enter the Krebs cycle?
What happens to the components of proteins which do not enter the Krebs cycle?
Protein are hydrolysed into their constituent amino acids, which are deaminated in the liver, forming a keto acid and ammonia.
- Ammonia is converted to urea and excreted
- Some keto acids are fed into glycolysis and some others are fed into the Krebs cycle
Definition of anaerobic respiration?
The breakdown of molecules in the absence of oxygen, releasing relatively little energy, making a small amount of ATP by substrate level phosphorylation
