Sigma seems to stimulate both initiation and elongation.

TLS Online TPP Program

#Id: 8560

#Unit 1. Molecules and their Interaction Relevant to Biology

TLS Online TPP Program

#Id: 8561

#Unit 1. Molecules and their Interaction Relevant to Biology

Uncompetitive inhibitors bind only to the enzyme-substrate complex and not to the free enzyme. 

TLS Online TPP Program

#Id: 8562

#Unit 1. Molecules and their Interaction Relevant to Biology

In neither case does the inhibitor compete with the substrate for the same binding site, so the inhibition cannot be overcome by increasing the substrate concentration.

TLS Online TPP Program

#Id: 8563

#Unit 1. Molecules and their Interaction Relevant to Biology

Substrate-binding could cause a conformational change to take place in the enzyme and reveal an inhibitor binding site, or the inhibitor could bind directly to the enzyme-bound substrate. 

TLS Online TPP Program

#Id: 8564

#Unit 1. Molecules and their Interaction Relevant to Biology

TLS Online TPP Program

#Id: 8565

#Unit 1. Molecules and their Interaction Relevant to Biology

In the simplest possible model, simple linear non-competitive inhibition, the substrate does not affect inhibitor-binding.