The excess energy of electron is used in the synthesis of ATP and the process is called

Options

A. Oxidative phosphorylation
B. Substrate phosphorylation
C. Photophosphorylation
D. Phosphorylation

Answer

To answer the question, "The excess energy of electron is used in the synthesis of ATP and the process is called," we need to analyze the options provided and understand the context of ATP synthesis.

### Step-by-Step Solution:

1. **Understanding Electron Energy**: The question mentions "excess energy of electrons." In biological systems, electrons are often transferred through a series of reactions, releasing energy that can be harnessed for various processes, including ATP synthesis.

2. **Identifying the Process**: The synthesis of ATP from ADP and inorganic phosphate (Pi) occurs through various mechanisms. The key processes to consider are:
- **Oxidative Phosphorylation**: This occurs in the mitochondria during cellular respiration, where energy from electrons is used to pump protons across a membrane, creating a gradient that drives ATP synthesis.
- **Photophosphorylation**: This occurs in chloroplasts during photosynthesis, where light energy is used to produce ATP.
- **Substrate-Level Phosphorylation**: This occurs in glycolysis and the Krebs cycle, where ATP is produced directly from a phosphorylated substrate.

3. **Analyzing the Options**:
- **Oxidative Phosphorylation**: Involves electron transport and proton gradient formation, but it is specific to respiration.
- **Substrate Phosphorylation**: Involves direct transfer of phosphate but does not primarily rely on electron energy.
- **Photophosphorylation**: Involves light energy, not just electron energy.
- **Phosphorylation**: A general term that refers to the addition of a phosphate group to a molecule, which can include all the above processes.

4. **Conclusion**: Since the question does not specify the context (whether it is respiration or photosynthesis), the most appropriate answer that encompasses the use of excess energy from electrons in ATP synthesis is simply "phosphorylation."

### Final Answer:
The excess energy of electrons is used in the synthesis of ATP, and the process is called **phosphorylation**.

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