Formation of Acetyl Co-enzyme A

Abstract:

This page explains the formation of Acetyl Co-enzyme A which is key to the synthesis of many organic molecules in cells. An acetyl group is a simple two-carbon-atom molecule which is sufficiently reactive to make it possible to use as a building block for larger carbon skeletons.

A large number of molecules that are synthesised in cells are built from two-carbon acetyl groups. An acetyl group derives from ethanoate (acetate) and is named acetyl when it forms a group within a larger molecule. Instead of using free acetate molecules the cell 'activates' the molecule by attaching it to Coenzyme A (CoA).

The acetyl group can derive from pyruvate (and ultimately from monosaccharides if that is the main 'food' for the cell). The two processes of oxidising/decarboxylating pyruvate and attaching the resulting acetyl group to CoA are coupled.

Oxidative decarboxylation is catalyzed by the pyruvate dehydrogenase complex. It is a multimeric assembly of three kinds of enzyme that implements the process in four steps. The animation shows all four steps in sequence and data sheets follow.

Subject:

Science and Technology

Grade Level:

Secondary, Post-secondary

Collection:

Terra Vivida