Final answer:
The product of Cyclin combining with Cdk is a phosphorylated Cdk/cyclin complex, which is key for cell cycle progression. These complexes activate other proteins by phosphorylating them, ensuring controlled cell division through various checkpoints.
Step-by-step explanation:
When Cyclin combines with Cdk, the product is a Cdk/cyclin complex which is necessary for the progression of the cell cycle.
Cyclins are regulatory proteins that control the progression through the cell cycle by forming complexes with Cyclin-dependent kinases (Cdks). These complexes must be phosphorylated at specific sites to become fully active. The phosphorylated Cdk/cyclin complexes can then phosphorylate other proteins, changing their shape and activating them, which allows the cell to advance to the next phase of the cell cycle. While concentrations of cyclin fluctuate, determining the timing for the formation of Cdk/cyclin complexes, the levels of Cdk proteins remain relatively stable throughout the cell cycle. Each pairing of different cyclins and Cdks regulates distinct checkpoints within the cell cycle, allowing for precise control of cell division.
- Cyclins bind to Cdk, forming the Cdk/cyclin complex.
- These complexes are phosphorylated to become fully active.
- Active Cdk/cyclin complexes phosphorylate other proteins, activating them to progress through the cell cycle.
- The levels of cyclins fluctuate, which determines the formation and activation of the Cdk/cyclin complexes.
- The complexes control specific checkpoints in the cell cycle, based on the combinations of cyclins and Cdks.