By: Jessica Green, CAPS Chemistry and Biology Student Manager
Say that you’re at your Soul Cycle class and you are working hard. Your muscles begin to burn, you’re damp with sweat, and your heart is pounding. How do all of these events effect the cells in your body? Your muscle fibers stretch and microtear, your glands produce sweat and skin cells shed, and your cardiac muscle is actively reshaping and conditioning. For all of these processes to happen, you have to be able to get rid of old cells and replace them with new, functioning cells. How does this happen?
For this we go to one of the fundamental of biology – all cells come from pre-existing cells. Cells go through the process of mitosis to replicate. Mitosis is the basic splitting of one cell into two daughter cells. However, mitosis is part of a bigger process. This process is called the cell cycle. The cell cycle is split into five phases: phase, S phase, mitotic phase, and cytokinesis phase. Additionally, there is a phase, which means that the cell is in arrest and is not actively dividing. The phase consists of everything in the cell being replicated except for the chromosomes, this includes the organelles. Next comes S phase, this phase is crucial because it is when the chromosomes replicate. After this is complete, phase occurs. phase consists of the cell taking a second to proofread and make sure that everything is ready for division. Once the cell is ready it enters the mitotic phase, which is where mitosis occurs. After mitosis cytokinesis occurs to split the cell into two. From here, we are back at .
Obviously, this must be a highly regulated process because creating defective cells can cause detrimental effects. There is a checkpoint that occurs before the cell can enter S phase. There is also a checkpoint that the end of , before mitosis. Lastly, there is a mitotic checkpoint before mitosis ends. These checkpoints ensure proper DNA replication and division. If any of these checkpoints are not met apoptosis occurs. It is when these check points are defective that cancer can proliferate. If you have any questions about any of this, please come see us at CAPS on the third floor of Zimmerman, click here to see all of our hours!