
The Citric Acid Cycle (Krebs cycle) involves several organic acids with different carbon numbers. The key acids with 4, 5, and 6 carbons are:
Succinic acid (4C) - A 4-carbon intermediate formed after the decarboxylation of α-Ketoglutaric acid.
α-Ketoglutaric acid (5C) - A 5-carbon compound that undergoes oxidative decarboxylation to form Succinyl-CoA.
Citric acid (6C) - The 6-carbon compound formed initially by the condensation of oxaloacetate and acetyl-CoA.
Thus, the correct answer is (D) Succinic acid, α-Ketoglutaric acid and Citric acid, as these represent the 4C, 5C, and 6C acids respectively in the Citric Acid Cycle.
The citric acid cycle features organic acids with varying carbon numbers, each playing specific roles. Citric acid, a six-carbon compound, is formed from the condensation of oxaloacetate (4C) and acetyl-CoA (2C). Through decarboxylation, citric acid is converted to α-ketoglutaric acid, a five-carbon molecule, releasing CO₂ and NADH. Further decarboxylation yields succinyl-CoA, which is eventually converted to succinic acid, a four-carbon compound. These intermediates highlight the stepwise breakdown of acetyl-CoA, linking glycolysis to oxidative phosphorylation for ATP production.
Thus, the correct answer is (D) Succinic acid, α-Ketoglutaric acid and Citric acid
| Column I | Column II | ||
|---|---|---|---|
| 1. | Calotropis | p. | Invertebrates |
| 2. | Pisaster | q. | Distasteful |
| 3. | Monarch butterfly | r. | Cryptically colored |
| 4. | Frogs | s. | Cardioglycoside |
Match Column I and Column I
| Column I | Column II | ||
|---|---|---|---|
| 1 | Narrowly utilitarian argument | p | Conserving biodiversity for major ecosystem services |
| 2 | Broadly utilitarian argument | q | Every species has an intrinsic value and moral duty to pass our biological legacy in good order to future generation. |
| 3 | Ethical argument | r | Receiving benefits like food, medicine & industrial products. |
It is the release of a relatively large amount of energy in cells by the breakdown of food substances in the presence of oxygen:
Glucose + Oxygen → Carbon Dioxide + Water.