Match the number of carbon atoms given in List - I with that of the compounds given in list - II and select the correct option.

Options

A. A - 2,B - 5,C - 3,D - 1
B. A - 5,B - 1,C - 4,D - 2
C. A - 3,B - 1,C - 4,D - 2
D. A - 5,B - 3,C - 1,D - 2

Answer

B

Explanation

* Kreb cycle starts with the 2carbon atom acetyl group with oxaloacetic acid (4c) and water to yield citric acid (6C) . This reaction is catalyzed by citrate synthase and a molecule of COA is released.
* Citric acid changes to is aconitic acid by the action of aconites. Then, is- aconitic acid changes to isocitrate by the same enzyme
* Isocitrate is changed into oxalosuccinate. One molecule `NADH_2` being produced. Then oxalosuccinate (6C) is converted to ketoglutaric acid (5C)
* D-ketoglutaric dehydrogenate complex converts it into a four-carbon atom succinyl - COA .
* During this step `CO_2` is released and `NAD^(+)` is reduced to `NADH + H^(+)` .
* In the next step succinate thiokinase catalyzes the conversion of succinyl COA to succinic acid.
* Fumaric acid is formed in the next step this reaction is catalyzed by succinate dehydrogenase.
* During this reaction, FAD the molecule is reduced to `FADH_2` .
* Malic acid is formed by the action of fumarase on fumaric acid. This step involves the addition of a water molecule.
* Regeneration of oxaloacetic acid is the last step catalyzed by malic dehydrogenase which reduced `NAD^(+)` to `NADH^(+) H^(+) `.