How many ATP and GTP molecules are required respectively for incorporatin of 25 amino acids in peptide chain ?

Options

A. 20 ATP, 20 GTP
B. 25 ATP, 25 GTP
C. 50 ATP, 50 GTP
D. 25 ATP 50 GTP

Answer

To determine how many ATP and GTP molecules are required for the incorporation of 25 amino acids into a peptide chain, we can break down the process as follows:

### Step 1: Understand the Activation of Amino Acids
- Each amino acid must be activated before it can be incorporated into a peptide chain. This activation occurs when the amino acid is attached to its corresponding tRNA.
- The activation process requires 1 ATP molecule for each amino acid.

### Step 2: Calculate ATP for Activation
- Since we need to activate 25 amino acids, the total ATP required for this step is:
\[ \text{Total ATP for activation} = 25 \text{ amino acids} \times 1 \text{ ATP/amino acid} = 25 \text{ ATP} \]

### Step 3: Understand the Incorporation of Amino Acids
- After activation, each amino acid is incorporated into the growing peptide chain. This incorporation requires energy in the form of GTP.
- Specifically, the incorporation of each amino acid requires 2 GTP molecules.

### Step 4: Calculate GTP for Incorporation
- For 25 amino acids, the total GTP required for incorporation is:
\[ \text{Total GTP for incorporation} = 25 \text{ amino acids} \times 2 \text{ GTP/amino acid} = 50 \text{ GTP} \]

### Final Answer
- Therefore, the total number of ATP and GTP molecules required for the incorporation of 25 amino acids into a peptide chain is:
- **25 ATP**
- **50 GTP**

### Conclusion
- The correct answer is **25 ATP and 50 GTP**.

---