Mitosis
Misc. facts
occurs in somatic cells; does not involve gametes (which occurs in meiosis)
Interphase
Functions in growth, DNA replication, and cell functions
90% of the cell cycle is interphase, 10% is mitosis
Mitosis Pathway
Metaphase
Prophase
Anaphase
Telophase
Nucleus present but degrades
Chromatin condenses into chromosomes and sister chromatids form
Chromosomes line up in middle of cell
Sister chromatids are separated via spindles of centrioles
Chromatids are on separate ends
Two new nuclei form
Cytokinesis
Cytoplasm is split
Chromosomes
46 chromosomes
Cells (somatic) with two sets of chromosomes are diploid
Cells (gametes) with one set of chromosomes are haploid
DNA is chromatin at this point
In preparation for prophase, centrioles duplicate and DNA replicates to give two copies of DNA
Microtubules begin extending from centrioles
This occurs via motor proteins (one of either side of the centromere) called centromere associated protein e
Motor proteins attach to microtubules
Dynein tightens the microtubule slack by bouncing back from side to side and tightening the microtubules until the chromosomes are in the middle
Chromosomes relax back into chromotin
Cleavage begins
The first step of interphase is G1 (gap 1), where the cell grows
Next is S (synthesis) phase, where DNA is copied
IN G2, the cells grow again
Cells in G0 phase (such as nerves and muscles) do not copy themselves
The spindle attaches to the kinetochore
Prometaphase
Microtubules attach to kinetochores
Checkpoints
Occurs at G1, S, end of G2, and M phases
The checkpoints occur through cyclin and protein kinases via phosphorylation cascade
Phosphorylation is adding a phosphate group to another molecule
Some kinases must be bound to a cyclin to be activated (CDK)