Microtubules Essay Example | Topics and Well Written Essays - 1750 words

Microtubules - Essay Example Microtubules are polymers that have elongated tube-like monomer chains. These chains are helical like. ÃŽ ±-ÃŽ ²tubulin subunits make up the helical tube that has 13 protofilaments that are aligned in a parallel way. The subunits enable the tube-like monomers to link with each other using vertical and lateral bonds. The ÃŽ ±-tubulin domain bind to the ÃŽ ²-tubulin domain forming these bonds. Hence, the mechanical strength of the microtubules is enhanced. The Microtubule Organizing Centre mediates the nucleation of the microtubules. It comprises a ring complex of ÃŽ ³-TURC and ÃŽ ³-tubulin (Atkinson, 2014, 5870). The specific ring complex serve as the template of the 13 subunits of the microtubules. Microtubules grow from the minus to the positive side. The minus side is located at the centrosome. The growth occurs towards the outer region to the cortex. The overall characteristic of the microtubules is the propensity for dynamic instability. Thus, the microtubules can shrink and grow randomly. The characteristic is associated with loss of the â€Å"GTC-cap. The loss is produced as new subunits are added. There is an ATP unit that is located in the ÃŽ ²-tubulin part of the microtubules. The ATP unit goes through hydrolisation as the filament grows (Alieva, 2014, 670). There is a disadvantage to this growth. If the hydrolisation is more rapid than the rate of the addition of monomers, it compromises the microtubule. There is a GDP bound type of the ÃŽ ²-tubulin that has a higher dissociation energy in comparison to the one that is bound by the ATP. It makes it more energetic for the microtubule de-polymerization. Hydrolisation enables the formation of ADP. It raises the likelihood of the microtubules being spoilt. They can be spoilt through reduction in the length and de-polymerization. The speed of spoilage of the microtubules is influenced by factors like proteins that bind along their