Formation of ATP in respiration is called

Options

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

Answer

**Step-by-Step Solution:**

1. **Understanding ATP**: ATP stands for adenosine triphosphate, which is known as the energy currency of the cell. It consists of adenosine and three high-energy phosphate bonds.

2. **Types of Phosphorylation**: There are different types of phosphorylation processes that lead to the formation of ATP:
- **Photophosphorylation**: This is the formation of ATP using light energy, primarily occurring during photosynthesis.
- **Substrate-level phosphorylation**: This occurs during the breakdown of glucose in cellular respiration, specifically during glycolysis and the Krebs cycle. Here, ATP is formed directly from the energy released during the conversion of substrates.
- **Oxidative phosphorylation**: This occurs in the electron transport chain (ETC) and involves the production of ATP through the transfer of electrons and the establishment of a proton gradient.

3. **Identifying the Correct Term**: In the context of respiration, the formation of ATP primarily occurs through substrate-level phosphorylation during glycolysis and the Krebs cycle. Therefore, the correct term for the formation of ATP in respiration is "substrate-level phosphorylation."

4. **Conclusion**: The formation of ATP in respiration is specifically referred to as substrate-level phosphorylation.

**Final Answer**: The formation of ATP in respiration is called substrate-level phosphorylation.

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