Introduction to Cell Cycle Checkpoints

What you’ll learn to do: Identify and explain the important checkpoints that a cell passes through during the cell cycle

As we just learned, the cell cycle is a fairly complicated process. In order to make sure everything goes right, there are checkpoints in the cycle:

There are three primary checkpoints in the cell cycle: The cell growth checkpoint, which takes place toward the end of growth phase one (G1); the DNA synthesis checkpoint, which takes place during the synthesis phase (S); and the mitosis checkpoint, which takes place during the mitosis phase. The cell growth checkpoint, checks whether the cell is big enough and has made the proper proteins for the synthesis phase. If not, the cell goes through a resting period (G0) until it is ready to divide. The DNA Synthesis Checkpoint checks whether DNA has been replicated correctly. If so, the cell continues on to mitosis (M). The mitosis checkpoint checks whether mitosis is complete. If so, the cell divides and the cell cycle repeats.

Let’s learn more about these different checkpoints and how they help control the cell cycle.