Mitosis (M Phase) Flashcards
Name the 6 steps of Mitosis
Prophase, Metaphase, Anaphase, Telophase, Karyokinesis, Cytokinesis
What occurs in Prophase of Mitosis?
(Nuclear envelope, Nuclear membrane, Chromatin)
What enzyme is needed?
Nuclear envelope disassembles
Nuclear membrane fragments into smaller vesicles (associated w/ Endoplasmic Reticulum)
Chromatin condenses into chromosomes
Lamin Kinase
What occurs in Metaphase of Mitosis?
Some microtubules attach to kinetochores
Spindle apparatus forms
Chromosomes align on equator of spindle
What are the 3 parts of the Spindle Apparatus?
Microtubules (MT)
Centrosome - contains centrioles + makes MTs
Kinetochore - attaches MTs + allows movement in Anaphase
What occurs in Anaphase of Mitosis?
Sister chromatids separate by breakdown of spindle MTs
What is the proposed mechanism for motility of sister chromatids during Anaphase of mitosis?
Protein in kinetochore contains ATPase
Force generate molecules associated w/ spindle MTs
What occurs in Telophase of Mitosis?
Daughter chromatid segregated at spindle poles
Nuclear envelope reforms around each set of chromosomes
Chromosomes decondense into chromatin
Dissolution of mitotic apparatus
What enzyme is needed during the Reformation of the nuclear envelope around each chromosome of Telophase?
Activated Lamin Phosphatase
What occurs in Karyokinesis?
The nucleus divides
What causes Cytokinesis? What occurs in Cytokinesis? What is this mechanism similar to?
Contractile ring of actin + myosin microfilaments
- encircle cortex overlying area of metaphase plate
Similar mechanism to SmM contraction
Define Chromosome
2 sister chromatids connected by centromere
Kinetochore on either side of centromere - allows chromosome to attach + move on MTs
Telomere protects ends of chromosome (exercise lengthens telomeres)
