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 $\rightarrow$ 3-phosphoglycerate + ATP
Phosphoenol pyruvate + ADP $\rightarrow$ pyruvate + ATP
Acetyl phosphate + ADP $\rightarrow$ 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.
