In the given scheme of ``Respiratory electron transport and oxidative phosphorylation'' identify A, B, C and D
Show Hint
Trace the electron flow:
NADH $\rightarrow$ I $\rightarrow$ Q $\rightarrow$ III $\rightarrow$ Cyt c $\rightarrow$ IV $\rightarrow$ Oxygen.
Succinate $\rightarrow$ II $\rightarrow$ Q...
A-Cytochrome C reductase; B-NADH dehydrogenase; C-Succinic dehydrogenase; D-Cytochrome C oxidase
A-Succinic dehydrogenase; B-Cytochrome C reductase; C-NADH dehydrogenase; D-Cytochrome C oxidase
A-NADH dehydrogenase; B-Cytochrome C reductase; C-Succinic dehydrogenase; D-Cytochrome C oxidase
A-Cytochrome C oxidase; B-Succinic dehydrogenase; C-Cytochrome C reductase; D-NADH dehydrogenase
Show Solution
The Correct Option isD
Solution and Explanation
Step 1: Analyze the Diagram:
D (Complex I): Accepts electrons from NADH ($NADH \rightarrow NAD^+$). This is NADH dehydrogenase.
B (Complex II): Feeds electrons into the Ubiquinone pool but does not pump protons. This is Succinic dehydrogenase.
C (Complex III): Receives electrons from Ubiquinone and passes them to Cytochrome c. This is the Cytochrome $bc_1$ complex or Cytochrome c reductase.
A (Complex IV): Receives electrons from Cytochrome c and reduces Oxygen to Water ($O_2 \rightarrow H_2O$). This is Cytochrome c oxidase.
Step 2: Match with Options:
A = Cyt C oxidase, B = Succinic dehydrogenase, C = Cyt C reductase, D = NADH dehydrogenase.
This sequence corresponds to Option (D).
