What is the substrate for the elongation of fatty acids?

What is the substrate for the elongation of fatty acids?

Microsomal fatty acid elongation represents the major pathway for determining the chain length of saturated, monounsaturated, and polyunsaturated fatty acids in cellular lipids. The overall reaction for fatty acid elongation involves four enzymes and utilizes malonyl CoA, NADPH, and fatty acyl CoA as substrates.

How can a fatty acid be elongated?

In eukaryotes, longer fatty acids are formed by elongation reactions catalyzed by enzymes on the cytosolic face of the endoplasmic reticulum membrane. These reactions add two-carbon units sequentially to the carboxyl ends of both saturated and unsaturated fatty acyl CoA substrates.

Where is fatty acid elongation carried out by the cells?

Fatty acid synthesis is the creation of fatty acids from acetyl-CoA and NADPH through the action of enzymes called fatty acid synthases. This process takes place in the cytoplasm of the cell.

How are fatty acids desaturated?

The desaturation of a fatty acid is an oxidation reaction that requires molecular oxygen and two electrons; however, oxygen itself is not incorporated into the fatty acid chain but is released in the form of water (Figure 3). Figure 3. Desaturation of stearoyl-CoA by stearoyl-CoA desaturase (SCD).

What are the two major fatty acid elongases?

To generalize, the fatty acid elongases can be divided into two major groups: (a) enzymes which are suggested to be involved in the elongation of saturated and monounsaturated VLCFA (ELOVL1, 3 and 6) and (b) enzymes which are elongases of polyunsaturated fatty acids (PUFA) (ELOVL2, 4 and 5).

How are fatty acid elongases carried out in mice?

The family of enzymes consists of at least six members in mouse and human, believed to carry out substrate-specific elongation with fatty acids of different lengths and degrees of unsaturation. The ability to synthesize VLCFA is a ubiquitous system found in different organs and cell types. However, VLCFAs seldom occur unesterified.

Where does microsomal fatty acid elongation take place?

Microsomal fatty acid elongation The predominant pathway for fatty acid elongation occurs in the ER and uses malonyl-CoA and fatty acyl-CoAs as substrates for addition of two carbon atoms to the existing fatty acid substrates.

How are fatty acids elongated in the endoplasmic reticulum?

In endoplasmic reticulum the reactions resemble those of de novo fatty acid synthesis. The overall reaction: This shows the overall process of fatty acyl elongation in the endoplasmic reticulum. The process resembles that catalyzed by fatty acyl synthase, but the individual activities appear to be on separate enzymes.