Cell Cycle 2 Flashcards
What happens during mitosis?
condensation of chromosomes
assembly of mitotic spindles
breakdown of nuclear envelope
attachment of chromatids to spindle
What does condensin do?
forms ring like structure and uses ATP to promote compaction and resolution of sister chromatids
_____ triggers the assembly of mitotic spindle
M-Cdk
Microtubules are made of _____ subunits
tubulin
What is tubulin?
a hetero dimer of alpha and beta tubulin with nonconvalent bonds
The plus end of a microtubule is _______ growing, and the minus end is _____ growing
fast; slow
What are the three types of microtubules?
kinetochore microtubules
interpolar microtubules
astral microtubules
What do kinetochore microtubules do?
attach each chromosome to spindle pole
What do inter polar microtubules do?
hold two halves of spindle together
What do astral microtubules do?
interact with cell cortex
The plus end of ______ microtubules are attached to sister chromatid pairs at large protein structures called kinetochores and to centromere
kinetochores
plus end of ____ microtubules coming from one pole interact with plus ends from other pole
interpolar
_____ microtubules radiate outward from the poles and contact the cell cortex helping to position the spindle in the cell
astral
Where are microtubules nucleated from?
microtubule organizing center (MTOC)
What is y-tubulin involved in?
nucleation of microtubule growth
y- tubulin ring complex (y-TuRC) is responsible for what?
nucleation of microtubule growth
What does y-turc bind to?
negative end to nucleate and elongate microtubules
Protein organelles are called ______ and consist of matrix and a pair of ______
centrosomes; centrioles
Dyneins move to _____ of cell and are ____ end directed
center; minus
Kinesins move toward ____ of cell, and walk toward ____ end of microtubules
periphery; plus
What is kinesin-5?
two motor domains that interact with plus end of anti parallel microtubule
Kinesin-5 motors move two anti parallel microtubules past each other to for or push the spindle pole ____
apart
PINK walks toward ____
plus end to force centrosomes apart
What is kinesin 14?
minus oriented directed motor with a single motor domain
What is kinesin 4, 10?
also called chromokinesin, plus directed motors
What is a class 1 extracellular signaling molecule?
mitogens: stimulate cell division by triggering G1/S -Cdl activity
What is a class 2 extracellular signaling molecule?
growth factors- stimulate cell growth
What is a class 3 extracellular signaling molecule?
survival factors- suppress form of programmed cell death (apoptosis)
What is Rb? and how can mutation lead to retinoblastoma?
tumor suppressor
if there are loss of copies of the Rb gene, then it can lead to cell and tumor proliferation of retina
What does ATM do?
senses DNA damage
What are the substrates of ATM? what do they activate?
Chk1 and Chk2 which activate p53
What are the three mechanisms to coordinate cell growth with division?
- rate of cell division determined by extracellular factor leading to cell growth
- cell growth and division controlled separately by growth factors and mitogens
- cell growth and division both stimulated by extracellular factor
