CH 14 & 15 Mitosis and Cell Cycle Flashcards
What moves sister chromatids apart in anaphase b
Motor proteins that pull and push.
What motor protein pulls
Dyein
What motor protein pushes
Eg5
How does the centrosome duplicate
By duplication of centrioles
Define Cohesins
Binds Chromatids and help alignment
T/F Cohesins helps the cell remember gene expression , by marking transcription factor binding, helping transcription factors find their correct places.
True
Ubiquitination events
Ubiquitination of cyclin and ubiquitination of CKI
What does Ubiquitination of CKI do?
Returns to the cell cycle.
What does Ubiquitination of cyclin do?
Activates/ inhibits CDK
How is Ubiquitination of CKI Regulated
By ubiqitin
How is ubiquitination of cyclin regulated
By phosphate
What are ATR and ATM doing on Chk1 Chk2.
Initiate Checkpoint response
What are the events of prophase
Condensing of chromosomes, Centrosomes appear
What are Chk1 and Chk2
They are mediator proteins
How do Chk1 and Chk2 interact with Cdc25
they target Cdc25
What do Chk1 and Chk2 do?
They Slow/ damage DNA replication
Function of Anaphase promoting cmoplex
activate seperase and allow chromatids to separate
How many kinetochore are there in a human cell
2 per chromosomes = 92 total.
What are astral microtubule
microtubules that attach to kinetochores
Where to astral microtubules originate
Centrosomes
What is the mitotic spindle
Lining and segregation of chromosomes
How does cdc25 affect commitment to mitosis
Catalyzes cyclin b and cdk1
T/F Cdc25 expression oscillates during cell cycle.
True
How is the ORI (origin of replication) licensed to fire
Licensing factor: Proteins that allow ORI to replicate DNA
How does spindle position determine contractile ring?
Because to the interaction between mitotic spindle and cortex of the cell.
How is coordination of DNA synthesis and replication of centrioles acheived
Centrioles replicates and is elongated in S phase with DNA synthesis.
Where does the signal for spindle assembly checkpoint (SAC) come from
Signal comes from the proper attachment of microtubules to kinetochore
Critical events of M phase
Nuclear and cytoplasmic division.
What is the pre-replication complex
6 protein complex bound to origin replication complex (ORC)
What happens to a cell without functional retinoblastoma protein.
DNA will not replicate or divid properly
How do oncologists classify Retinoblastoma protein
Cancer suppressor
What are centromeres
Centromere is the origin of a chromosome
What is the role of a centromere
The binding site of kinetochore and microtubule.
T/F When nuclear envelope breaks down, microtubules attach to chromosome by randomly probing and finding kinetochore.
True
What molecular sensors respond to the absence of Retinoblastoma protein
G1 CDK-cyclin phosphorylate Retinoblastoma
Define Congression as it pertains to mitosis
aligning of mitotic spindle
T/F Chromosomes are pushed away from poles.
False
Cdk and Cyclin complex of G1 phase
Cyclin D
CDK 4 and CDK 6
CDK and Cylclin complex of S phase
Cyclin a
CDK 2
CDK and Cyclin complex of G2 phase
Cyclin A
CDK 1
CDK cyclin complex of M phase
Cyclin B
CDK 1
T/F Each kinetochore fiber exerts poleward force that is proportional to its lenght
True
Kinetochores need to be the same length
T/F Stable bipolar attachment of sister chromatids is assessed by kinetochore passenger proteins and MCAK motor (that depolymerizes microtubules) so that the SAC is not passed too soon.
False.
SAC becomes activated when there is an issue in the attachment of kinetochore.
A cell in quiescence is?
In arrested state.
T/F CENP-E protein in an unattached kinetochore can slide along an adjacent, attached kinetochore fiber toward a centered chromosome to help the unattched chromosome get closer to the center. This may help shorten the distance for the microtubles searching for an unattached kinetochore.
True
CENP-E is a part of the the corona
What does a cell look like when it losses function of Wee kinase the inhibitory kinase of Cdk1
The cell enters mitosis early.
Wee acts as a regulator for entry into mitosis
Role of SAC
To make sure kinetochores are properly attached.
What prevents ORI from being being used more than once per cell cycle.
Can no longer bind to DNA
The isolation of conditional cell cycle mutations in yeast helped identify many of the key proteins involved in cell cycle control. Many of these mutations were given the name cdc (cell division cycle) and are temperature sensitive. Hypothesize about the outcomes of a cdc temperature sensitive mutant.
Temperature can be used as a factor to determine the rate of cycle.
There are several mechanisms for regulating Cdk activiy. List 3.
Association with cyclin
Phosphorilation - inhibitory
Dephosphorilation- activation
Role of p53
is a gene that codes for regulation in DNA
less mutations
What is one function of Cdk1 - Cyclin B complex in mammalian cells
Mitosis, Phosphorilation of lamin protein, trigger of nuclear envelope disassembly
