For your responses please justify your answer. No justification for answer will

Question

For your responses please justify your answer. No justification for answer will recieve "needs work" rating.

32. Which statements concerning the regulation of CDK/cyclin complexes are correct?
A. At different points in the cell cycle, G1 and mitotic cyclins can activate the same CDK subunit.
B. Phosphorylation of CDK proteins can both activate and inhibit cyclin/CDK activity.
C. If CAK has phosphorylated the CDK subunit, CDKs will remain active in the absence of cyclin.
D. The CDK/G1 cyclin complexes that control S phase initiation are likely to have signal sequences
that target them for nuclear import.
F. Cyclin/CDK complexes are frequently targets of cell cycle checkpoint pathways.

33. Which of the following statements concerning ubiquitin-mediated proteolysis are correct?
A. Ubiquitin modification serves as a molecular “tag” to signal degradation by the proteosome.
B. Both G1 and mitotic cyclins are targets for ubiquitin-mediated proteolysis.
C. Nuclear envelope breakdown during mitosis is accomplished by ubiquitin-mediated
proteolysis of lamin intermediate filament proteins.
D. The separation of sister chromatids at the metaphase to anaphase transition is controlled by
ubiquitin-mediated proteolysis of an anaphase inhibitor.
E. Conditional mutations that inactivate the gene encoding ubiquitin in yeast would be expected
to exhibit a cdc phenotype.

Explanation / Answer

32. Which statements concerning the regulation of CDK/cyclin complexes are correct?
A. At different points in the cell cycle, G1 and mitotic cyclins can activate the same CDK subunit.
B. Phosphorylation of CDK proteins can both activate and inhibit cyclin/CDK activity.
C. If CAK has phosphorylated the CDK subunit, CDKs will remain active in the absence of cyclin.
D. The CDK/G1 cyclin complexes that control S phase initiation are likely to have signal sequences
that target them for nuclear import.
F. Cyclin/CDK complexes are frequently targets of cell cycle checkpoint pathways.

Phosphorylation of CDK proteins can both activate and inhibit cyclin/CDK activity.

Phosphorylation of CDK subunit only after cyclin binding.

Phosphorylation of CDK proteins-reversible modification

33. Which of the following statements concerning ubiquitin-mediated proteolysis are correct?
A. Ubiquitin modification serves as a molecular “tag” to signal degradation by the proteosome.
B. Both G1 and mitotic cyclins are targets for ubiquitin-mediated proteolysis.
C. Nuclear envelope breakdown during mitosis is accomplished by ubiquitin-mediated
proteolysis of lamin intermediate filament proteins.
D. The separation of sister chromatids at the metaphase to anaphase transition is controlled by
ubiquitin-mediated proteolysis of an anaphase inhibitor.
E. Conditional mutations that inactivate the gene encoding ubiquitin in yeast would be expected
to exhibit a cdc phenotype.

. Ubiquitin modification serves as a molecular “tag” to signal degradation by the proteosome.

it shows the cascade of Ubiquitinconjugated enzymes,(e2 and e3)

signal degradation by the proteosome occurs at multiple levels

Related Questions

Navigate

• Browse (All)
• Browse F
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.