Cyclin-dependent kinase (Cdk) is ________.
A) inactive, or "turned off," in the presence of cyclin
B) present only during the S phase of the cell cycle
C) an enzyme that removes hydroxyl groups from growth hormones
D) the enzyme that catalyzes the attachment of chromosomes to microtubules
E) an enzyme that attaches phosphate groups to other proteins

Question

Quizplus · Accepted Answer

Cyclin-dependent kinase (Cdk) is an enzyme that attaches phosphate groups to other proteins. Specifically, Cdks are activated by binding to cyclins, which are regulatory proteins that fluctuate in concentration throughout the cell cycle. Once activated, Cdks can phosphorylate specific target proteins, triggering events such as cell division.

Cyclin-Dependent Kinase (Cdk) Is ________