Question

Describe the structure of microtubules. Where would you expect to find the minus and plus ends.

Answer 1

now, mienotubules are polymer of 28-tubulin monomers here, the basie building blocks are dB tubulin heterodimer first, the & -B-tubulin heterodimens are arranged in a linear head-to-tail form to form a single line of XB-tubulin heterodimers. This storncture is known as proto filaments. Now, a number of proto silament lie parallel to each other giving rise a structure of microtubule. The following diagram ca minus end minus C- nd-subunit a protofilament he parallel to another -B-subunit a B-thebulin heterodimer 8plus-end oooo plusend porotor Microtubule filament - Usually os generally in cells 13 protofilament arranged in that type of tube-like stormeture to give a structure of microtubule. since, in microtubule is made-up due to parallel arrange- ment of each poro to filament. Thus, always one end oR one-face of microtubule consist either &- OR B-filament while the other face consist of B. OR &- filament de. one face made up of a filament while other made ub of B-filament of heterocimen. - The B-end which is fast growing end sepselent plus ends while &- filament end which is slow-growing represents minus ende.