Question

Identify if each of the following statements about tubulin and/or microtubules (MTs) is True or False.
(a) True False The local concentration of available GTP-bound tubulin can vary in different parts of the cell.
(b) True False A tubulin dimer with a GTP in the alpha subunit and a GDP in the beta subunit has greater affinity for an MT than a tubulin dimer where GTP is bound in both subunits.
(c) True False In vivo, the plus end of an MT polymerizes at the same rate as the minus end.
(d) True False An MT is made of 13 linear protofilaments that surround a hollow core.

Answer 1

Ans.a) True

The local concentration of GTP-bound tubulin can vary in different parts of the cell.

Ans.b) false

Alpha tubulin in GTP form and beta tubuljn in GTP form have high affinity for microtubules.

Ans.c) false

Polymerization is fast at plus end( beta tubulin) and slow at minus end ( alpha tubulin).

Ans.d)True

An MT is made of 13 linear protofilaments that surround a hollow core.