AP BIOLOGY

Detailed explanation-1: -Of the many proteins involved in cell cycle control, cyclin-dependent kinases (CDKs) are among the most important. CDKs are a family of multifunctional enzymes that can modify various protein substrates involved in cell cycle progression.

Detailed explanation-2: -Cyclins are a family of proteins that regulate the timing of the cell cycle in eukaryotic cells.

Detailed explanation-3: -Answer and Explanation: Cell cycle regulation is controlled via the action of enzymes call cyclin dependent kinases and cyclins. These enzymes control the progression of the cell through all phases of interphase, as well as mitosis.

Detailed explanation-4: -Two groups of proteins, called cyclins and cyclin-dependent kinases (Cdks), are responsible for the progress of the cell through the various checkpoints. The levels of the four cyclin proteins fluctuate throughout the cell cycle in a predictable pattern ([link]).

Detailed explanation-5: -Cyclin A is a pivotal regulatory protein which, in mammalian cells, is involved in the S phase of the cell cycle. Transcription of the human cyclin A gene is cell cycle regulated.