Condensed Review Flashcards
(49 cards)
What phases are Cdks present in the cell cycle?
All phases
What does centromere protein A (CENP-A) do?
recruits proteins to the centromere from the kinetochore
What do cyclins do and how do they do it?
regulate cell cycle progression by activating Cdks
What does the Gap 2-M phase checkpoint do?
checks DNA replication status and the integrity of the DNA.
When is mitosis promoting factor (MPF) activated?
When it is singly phosphorylated
What does the Ubiquitin-proteasome pathway controls?
the degradation of regulatory proteins
What is the phosphorylation of condensin done by? What is the phosphorylation of condensin required for?
it is done by M-cyclin-M-Cdk. It is required for chromosome condensation.
Cyclin synthesis and degradation, Cdk phosphorylation, and Cdk dephosphorylation all do what?
regulate mitotic Cdk activity
After DNA replication, the sister chromatids are held together by what?
Cohesins
Condensins assemble or associates with DNA when what?
phosphorylated by M-Cdk
DNA damage causes elevated levels of p53, what does this result in?
the expression of Cdk inhibitor proteins such as p21
What does S-Cdk do to ensure that DNA replication only happens once?
it phosphorylates cdc60 and inactivates it.
Progression through the cell cycle requires a ____ to bind to a ____?
cyclin, Cdk
The binding of a cyclin to a Cdk is also required for what?
Cdk enzymatic activity
During anaphase, why are sister chromatids separated?
because securins are degraded and destroyed due to ubiquitination by APC
The Gap 1 DNA damage checkpoint inhibits cyclin-Cdk complexes by what?
p21 (p21 is a protein that muffles signaling from the cyclin-Cdk complex)
The concentration of M-cyclin falls where because of ubiquitination and degradation?
at about the end of M phase
The retinoblastoma (Rb) protein blocks cells from entering the cell cycle by doing what?
inhibiting cyclin transcription
M-Cdk stimulates or promotes the activity of APC. The APC promotes the degradation of proteins that regulate M phase and it inhibits M-Cdk activity.
just memorize this one idk what to make the question out of this.
Phosphorylation of mitotic Cdk by the inhibitory kinase (Wee1) makes the Cdk inactive, inhibiting the Cdc25 phosphatase will delay the G2/M transition and the activating phosphatase (Cdc25) removes the two phosphates from mitotic Cdk that were added by Wee1, so that M- Cdk will be active.
just memorize this one idl what to make the question out of this.
In what phase are sister chromatids separated
Anaphase II
When does meiosis most resemble mitosis?
In meiosis II
What is the result of Meiosis I
Two haploid cells
Meiosis includes ___ round of replication and ___ nuclear division(s)
one, two