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Cell Life Cycles

Our bodies, like all living material, are made up of cells. These microscopic building blocks reproduce asexually on a specific cycle. This life cycle includes interphase, which is broken up into four different segments, and mitosis or cell division. Cell life cycle changes occur in occasionally random moments. These phases of the cell's life cycle have very specific uses to the cell.

Gap 1
- Gap 1 is the first phase in the life cycle of a cell. During this phase, the cell is producing RNA. RNA is vital to the cell as it will be converted into DNA in later processes. The cells synthesize protein to create RNA. Towards the end of this stage, sensor mechanisms in the cell determine whether the cell has enough RNA available for DNA synthesis. This is known as the G1 checkpoint. If all is well, the cell will then move on to the next stage in the cycle.
S Phase
- It is in the S phase that the cell begins to replicate DNA. DNA contains the genetic information of the organism and must be duplicated exactly. The RNA produced in Gap 1 is synthesized into the appropriate strands of DNA inside the center of the cell. The DNA is stored here until the cell is ready to divide during mitosis.
Gap 2
- During Gap 2, the cell will continue to create proteins that are essential for mitosis. It no longer synthesizes RNA or DNA. The cell will grow in size to prepare to divide. The cell is preparing to meet the Gap 2 Checkpoint, which tests whether the cell is ready to divide. These requirements include having synthesized enough protein and grown large enough to support division.
Mitosis
- The cell stops growing and producing protein just before it begins mitosis. During this process, the cell focuses on dividing into two different cells. The DNA created during the interphase gives the cell instructions on division, including making parts for the new cell. These parts include a core, nuclear membrane, cell walls, the golgi bodies, the mitochondria and all other cell parts. The cell will continue to divide until the new cell breaks free. Mitosis takes about one to two hours.
Gap 0
- Gap 0 is a the period when a cell stops preparing for division. It stops synthesizing protein, creating RNA or duplicating DNA. Cells go into Gap 0 immediately following the mitosis process. It is essentially a resting period that prevents the cell from wearing out too early. Gap 0 can also be the permanent state of older or damaged cells that cease growing and dividing.

Nature