Which type of phosphorylation synthesizes ATP using an enzyme that transfers a phosphate group to ADP?

• A. Adaptive Phosphorylation.
• B. Oxidative Phosphorylation.
• C. Substrate-level Phosphorylation.
• D. Product-level Phosphorylation.

Answer: (C)

Verified step by step guidance

1. Understand the process of ATP synthesis: ATP (adenosine triphosphate) is synthesized by adding a phosphate group to ADP (adenosine diphosphate). This process can occur through different mechanisms.
2. Identify the types of phosphorylation: There are several types of phosphorylation processes, including substrate-level phosphorylation, oxidative phosphorylation, and others.
3. Define substrate-level phosphorylation: This is a type of phosphorylation where an enzyme directly transfers a phosphate group from a substrate molecule to ADP, forming ATP. It occurs in the cytoplasm during glycolysis and in the mitochondria during the Krebs cycle.
4. Differentiate from oxidative phosphorylation: Oxidative phosphorylation involves the electron transport chain and chemiosmosis, where ATP is synthesized using energy derived from the transfer of electrons in the mitochondria.
5. Conclude with the correct type: Based on the definition, substrate-level phosphorylation is the process where an enzyme directly transfers a phosphate group to ADP to synthesize ATP.