vincristine acts on the metaphase phase of cell cycle.
vincristine acts on the metaphase phase of cell cycle.
vincristine acts on which phase of cell cycle?
metaphase
the cell cycle is a process in which an ordered set of events leads to the growth and division into two daughter cells. the cell cycle is a cycle rather than a linear process because the two daughter cells produced repeat the cycle. this process contains two main phases, interphase, in which the cell grows and synthesizes a copy of its dna, and the mitotic (m) phase, during which the cell separates its dna and divides into two new daughter cells. interphase is further broken down into the g1 (gap 1) phase, s (synthesis) phase, g2 (gap 2) phase and the mitotic (m) phase which in turn is broken down into mitosis and cytokinesis. following cytokinesis, during g1 phase the cells monitor environment for the potential growth factors, grow larger and once achieve the threshold size (rrna and overall protein content characteristic for a given cell type) they start progression through s phase. during s phase, the cell also duplicates the centrosome, or microtubule-organizing center, which is critical for dna separation in the m phase. after complete synthesis of its dna, the cell enters the g2 phase where it continues to grow in preparation for mitosis. following interphase, the cell transitions into mitosis, containing four sub stages: prophase, anaphase, metaphase, and telophase. in mitosis, dna condenses into chromosomes, which are lined up and separated by the mitotic spindle. after duplicate dna is separated on opposite ends of the cell, the cytoplasm of the cell is split in two during cytokinesis resulting in two daughter cells.
g1/s transition
as the eukaryotic cell cycle is a complex process, eukaryotes have evolved a network of regulatory proteins, known as the cell cycle control system, which monitors and dictates the progression of the cell through the cell cycle. this system acts like a timer, or a clock, which sets a fixed amount of time for the cell to spend in each phase of the cell cycle, while at the same time it also responds to information received from the processes it controls. the cell cycle checkpoints play an important role in the control system by sensing defects that occur during essential processes such as dna replication or chromosome segregation, and inducing a cell cycle arrest in response until the defects are repaired. the main mechanism of action of the cell cycle checkpoints is through the regulation of the activities of a family of protein kinases known as the cyclin-dependent kinases (cdks), which bind to different classes of regulator proteins known as cyclins, with specific cyclin-cdk complexes being formed and activated at different phases of the cell cycle. those complexes, in turn, activate different downstream targets to promote or prevent cell cycle progression.
cell cycle checkpoint