Interphase And Three Stages And Overview Of The Cell Cycle

1541 Words 7 Pages
Cell cycle overview

The role of the cell cycle is to allow a cell to increase its mass, acquire nutrients, duplicate DNA and divide into daughter cells. There are three stages within the cell cycle, interphase, mitotic (M) phase and cytokinesis. Interphase is further divided into Gap 1 (G1), Synthesis (S) and Gap 2 (G2) where the main agenda for the cell is to grow, and obtain nutrients in preparation for the next phase. The next stage is the M phase and includes four consecutive events, prophase, metaphase, anaphase, and telophase over which the cell duplicates its genetic material before finally reaching cytokinesis, the third stage, in which the cell divides into two daughter cells. Cells may then enter a quiescent G0 phase, before beginning
…show more content…
The latter of which is also known as the ‘restriction’ point in mammalian cells and ‘start’ point in yeast cells. The restriction point exists to allow the cell to commit to a new cell cycle, and by doing so move into the G1 phase rather than stay in the dormant G0 phase. Both points are present to ensure proper cell division and timing of cellular events. Failure to meet the criteria set at each point has been shown to lead to uncontrolled cell division and essentially tumorigenesis due to mutations in regulatory proteins which keep the cell in a proliferative …show more content…
CDK1 creates a positive feedback loop by phosphorylating Wee1 to inhibit it and activate Cdc25. It is hypothesized that this behavior allows the cell to commit to mitosis even if cyclin B levels start to decline. Accumulation of activated cyclin B leads rapid translocation of the cyclin into the nucleus (wiki 12 G2 phase). Upon entering the nucleus, cyclin B – CDK1 begins to phosphorylate centrosomal proteins, histone H1, microtubule associated proteins (MAPs), and nuclear lamins all in preparation for mitosis (wiki 8

Related Documents