The provided reference discusses ADP-glucose, not ADP itself, and the enzyme that synthesizes it is ADPglucose pyrophosphorylase (APGase). Therefore, the reference does not directly answer "What enzyme makes ADP?". Based on general knowledge, here's a clarification: The question as is, needs clarification as ADP can be produced by multiple pathways and not by a single enzyme. Therefore, it is more accurate to ask what enzyme removes a phosphate from ATP to create ADP which has a single answer.
Here's a breakdown with more detail and the accurate enzyme involved:
The question is about the production of adenosine diphosphate (ADP), a crucial molecule in cellular energy processes. While ADP-glucose synthesis is discussed in the reference, it is important to distinguish it from the formation of ADP.
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What is ADP?
ADP, or Adenosine Diphosphate, is a nucleotide composed of an adenine base, a ribose sugar, and two phosphate groups. It plays a vital role in energy storage and transfer within cells. -
How is ADP formed?
ADP is primarily formed by the removal of one phosphate group from adenosine triphosphate (ATP). The enzyme primarily responsible for this process is ATPase. -
The Role of ATPase:
ATPase (or ATP hydrolase) is a class of enzymes that catalyzes the hydrolysis of ATP, resulting in ADP and inorganic phosphate (Pi). This process releases energy that cells can use for various functions. -
ADP in Starch Metabolism:
The reference mentions ADP-glucose, which is important for plant starch synthesis. Specifically, the enzyme ADPglucose pyrophosphorylase (APGase) synthesizes ADP-glucose, a precursor for starch (31). ADP-glucose is then polymerized by starch synthases (32). However, this process does not create ADP directly and is only related to ADP, being an ADP derivative.
| Molecule | Enzyme Involved | Reaction |
|---|---|---|
| ATP to ADP | ATPase | ATP -> ADP + Pi |
| Glucose to ADP-glucose | ADPglucose pyrophosphorylase (APGase) | Glucose-1-phosphate + ATP -> ADP-glucose + Pyrophosphate |
Summary:
While the provided reference is valuable for understanding ADP-glucose and plant starch metabolism, the enzyme directly making ADP from ATP is ATPase. ADP-glucose and therefore, its synthesis by APGase, is a separate process.
