Progression through the cell cycle is regulated by oscillations in the concentration of which type of molecule?
a. p53, Rb, and other tumor suppressors
b. Receptor tyrosine kinases
c. Cyclins
d. Cyclin-dependent kinases

Verified step by step guidance

1. Understand the cell cycle: The cell cycle is a series of phases that cells go through as they grow and divide. It includes the G1, S, G2, and M phases.
2. Identify the role of cyclins: Cyclins are proteins that regulate the progression of cells through the cell cycle by activating cyclin-dependent kinases (CDKs).
3. Recognize the oscillation pattern: Cyclins are named for their cyclical concentration changes during the cell cycle. Their levels rise and fall, which is crucial for the timing of cell cycle events.
4. Differentiate between cyclins and CDKs: While cyclins regulate the cell cycle by binding to CDKs, it is the concentration of cyclins that oscillates, not the CDKs themselves.
5. Conclude the answer: Based on the understanding that cyclins are the molecules whose concentrations oscillate to regulate the cell cycle, identify the correct option as cyclins.

Key Concepts

Cell Cycle

The cell cycle is a series of phases that cells go through as they grow and divide. It consists of interphase (G1, S, and G2 phases) and mitotic phase (mitosis and cytokinesis). Proper regulation of the cell cycle is crucial for normal cell function and prevention of uncontrolled cell division, which can lead to cancer.

Cyclins

Cyclins are a family of proteins that control the progression of cells through the cell cycle by activating cyclin-dependent kinases (CDKs). Their concentrations fluctuate throughout the cell cycle, peaking at specific phases to ensure the cell cycle progresses in a controlled manner. Cyclins bind to CDKs, forming a complex that phosphorylates target proteins to drive the cell cycle forward.

Cyclin-Dependent Kinases (CDKs)

Cyclin-dependent kinases (CDKs) are a group of protein kinases that, when activated by binding to cyclins, regulate the cell cycle. CDKs phosphorylate specific target proteins, leading to cell cycle progression. The activity of CDKs is tightly regulated by cyclins, ensuring that cell cycle events occur in the correct sequence and at the appropriate time.