What is the EC number classification for CK?

The correct classification for creatine kinase (CK) is 2.7.3.2. This classification falls under the category of transferases, specifically those enzymes that transfer phosphate groups. Creatine kinase catalyzes the reversible transfer of a phosphate group from ATP to creatine, resulting in the formation of ADP and phosphocreatine, which plays a crucial role in energy metabolism in muscle and brain tissues.

Understanding enzyme classification through the EC (Enzyme Commission) number system involves recognizing that the first digit represents the main class, the second digit indicates the subclass, and the third represents the sub-subclass. In this instance, the initial '2' signifies that CK is a transferase, the '7' indicates that it is involved in transferring phosphorus-containing groups, and the '3' specifies that the phosphate group is donated from ATP.

The other options represent different enzymes with distinct functions and do not pertain to creatine kinase. This specialized classification helps in identifying the specific enzymes and their roles in biochemical pathways.