3. (4pts each) Suppose you expose cells to drugs with the following effects. Wil

Question

3. (4pts each) Suppose you expose cells to drugs with the following effects. Will these tend to promote microtubule growth, shrinkage, or neither? Please provide a brief explanation. A. The drug inhibits the exchange of GTP into and GDP out of free tubulin dimers B. The drug inhibits hydrolysis of the GTP bound to tubulin in microtubules. C. The drug increases the affinity of tubulin dimers carrying GTP for other tubulin dimers. D. The drug increases the affinity of tubulin dimers carrying GDP for other tubulin dimers. E The drug increases theaffinty of alipha and beta tubulin monomers for each other within tubulin dimers.

Explanation / Answer

A. If there is the inhibition of exchange of GTP into GDP out of the free tubulin dimers than the shrinkage would be non-stop and eventually disappear because tubulin dimers with GDP have very low affinity for each other.

B. GTP bound to tubulin in microtubule hydrolyzed to promote the polymerization. Inhibition of hydrolysis will give rise to shrinkage of microtubule.

C. Dynamic instability results from the hydrolysis of GTP bound to beta-tubulin during or shortly after polymerization, which reduce the binding affinity for the adjacent molecule. So, increased affinity of GTP will promote the microtubule growth.

D. There will be no effect on microtubule growth by increasing the affinity of GDP.

E. The increased affinity of tubulin dimmers for each other will also not greatly affect the growth of microtubules.

Related Questions

Navigate

• Browse (All)
• Browse 3
• Subjects

---

---

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