How many high-energy phosphate bond equivalents are utilized in the process of activation of amino acids for protein synthesis?

Options

A. Four
B. Two
C. One
D. Three

Answer

To determine how many high-energy phosphate bond equivalents are utilized in the activation of amino acids for protein synthesis, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Amino Acid Activation**:
- Before protein synthesis can occur, amino acids need to be activated. This activation is crucial for ensuring that the correct amino acid is used and that there is enough energy for peptide bond formation.

2. **Role of ATP in Activation**:
- The activation of amino acids requires ATP (adenosine triphosphate). When an amino acid is activated, it reacts with ATP.

3. **Formation of Amino Acid-AMP Complex**:
- The reaction between the amino acid and ATP results in the formation of an amino acid-AMP (adenosine monophosphate) enzyme complex. During this reaction, a molecule of pyrophosphate (PPi) is released.

4. **Enzyme Involvement**:
- This reaction is catalyzed by the enzyme aminoacyl-tRNA synthetase.

5. **Energy Consideration**:
- The ATP molecule has three phosphate groups, and when it is converted to AMP and pyrophosphate, two high-energy phosphate bonds are utilized. This is because the pyrophosphate (PPi) itself consists of two phosphate groups, which are also considered high-energy bonds.

6. **Final Calculation**:
- Since the conversion of ATP to AMP and PPi results in the utilization of two high-energy phosphate bonds, we conclude that a total of **2 high-energy phosphate bond equivalents** are utilized in the activation of amino acids for protein synthesis.

### Final Answer:
The number of high-energy phosphate bond equivalents utilized in the process of activation of amino acids for protein synthesis is **2**.

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