Respiration in Plants Question 31
31. The number of substrate level phosphorylations in one turn of citric acid cycle is
[2020]
(a) One
(b) Two
(c) Three
(d) Zero
Show Answer
Answer : a
Hints & Solutions
(a) One substrate level phosphorylation in one turn of citric acid cycle as per following reaction: Another example of substrate level phosphorylation are as follows:
1,3-bisphosphoglycerate + ADP $arrow$
3-phosphoglycerate + ATP
Phosphoenolpyruvate $+ADP \to$ pyruvate + ATP Acetyl phosphate + ADP $arrow$ acetate + ATP (same mechanism for other alkanoic acids) Substrate-level phosphorylation is the production of ATP from ADP by a direct transfer of a high-energy phosphate group from a phosphorylated intermediate metabolic compound in an exergonic catabolic pathway. Oxidative phosphorylation is the process in which ATP is formed as a result of the transfer of electrons from $NADH$ or $FADH_2$ to $O_2$ by a series of electron carriers. This process, which takes place in mitochondria, is the major source of ATP in aerobic organisms.
