Final answer:
Cyclin-dependent kinases (Cdks) require phosphorylation by another kinase to become fully activated. They phosphorylate proteins involved in advancing the cell cycle, typically targeting the amino acids serine, threonine, and tyrosine.
Step-by-step explanation:
Cyclin-dependent kinases (Cdks) are protein kinases that require phosphorylation by another kinase to become fully activated. Cdks phosphorylate other proteins, including those involved in advancing the cell cycle. The amino acids that Cdks typically phosphorylate are serine, threonine, and tyrosine.