Given below are the steps involved in the citric cycle . Arrange them correct option.
i. Formation of alpha - ketoglutaric acid and succinyl - CoA.
ii. Condensation of acetyl group with oxaloacetic acid.
iii. Isomerization of citrate to isocitrate.
iv. Synthesis of GTP.

Options

A. i,iv , iii , ii
B. iii, iv , ii ,i
C. iv, i, ii , iii
D. ii, iii, i, iv

Answer

To solve the question regarding the arrangement of steps involved in the citric acid cycle, we will analyze each step and determine the correct order.

### Step-by-Step Solution:

1. **Identify the Steps:**
- i. Formation of alpha-ketoglutaric acid and succinyl-CoA.
- ii. Condensation of acetyl group with oxaloacetic acid.
- iii. Isomerization of citrate to isocitrate.
- iv. Synthesis of GTP.

2. **Understand the Citric Acid Cycle:**
- The citric acid cycle (also known as the Krebs cycle or TCA cycle) begins with the condensation of acetyl-CoA and oxaloacetic acid to form citric acid (citrate).

3. **Order the Steps:**
- **Step 1:** The cycle starts with the condensation of the acetyl group with oxaloacetic acid (Step ii).
- **Step 2:** This is followed by the isomerization of citrate to isocitrate (Step iii).
- **Step 3:** Next, the oxidative decarboxylation occurs, leading to the formation of alpha-ketoglutaric acid and succinyl-CoA (Step i).
- **Step 4:** Finally, succinyl-CoA is converted into succinate, which is coupled with the synthesis of GTP (Step iv).

4. **Final Arrangement:**
- The correct order of the steps is:
1. ii. Condensation of acetyl group with oxaloacetic acid.
2. iii. Isomerization of citrate to isocitrate.
3. i. Formation of alpha-ketoglutaric acid and succinyl-CoA.
4. iv. Synthesis of GTP.

### Correct Sequence:
- ii → iii → i → iv