The dependent variable is the rate of the reaction. 

The independent variables are the concentration of enzyme, the concentration of the substrate, the temperature, and the addition of an inhibitor

TLS Online TPP Program

#Id: 1509

#Unit 2. Cellular Organization

GTP-binding site on the β-subunit is at the surface of the dimer and GTP bound by the β-subunit can be hydrolyzed.

TLS Online TPP Program

#Id: 1510

#Unit 2. Cellular Organization

A microtubule is a hollow cylindrical structure built from 13 parallel protofilaments, each composed of αβ-tubulin heterodimers stacked head to tail and folded into a tube.

TLS Online TPP Program

#Id: 1511

#Unit 2. Cellular Organization

Tubulin dimers in which the β-subunit has bound GTP are added preferentially to (+) end of the microtubule.

TLS Online TPP Program

#Id: 1512

#Unit 2. Cellular Organization

In a microtubule,

The end with exposed β-subunits is the (+) end

The end with exposed α-subunits is the (−) end

 

TLS Online TPP Program

#Id: 1513

#Unit 2. Cellular Organization

Microtubules exist in three forms:

Singlet

Doublet

Triplet

TLS Online TPP Program

#Id: 1514

#Unit 2. Cellular Organization

Most microtubules in a cell consist of a simple tube, a singlet microtubule, built from 13 protofilaments.