Elongases in Lipid Biosynthesis

The video explains the process of fatty acid elongation, highlighting that fatty acid synthase can only produce fatty acids up to 16 carbons long, such as palmitate. To create longer fatty acids like stearic or arachidic acid, the body uses elongases, which are located in the smooth ER. These enzymes extend the fatty acid chain by two carbons at a time, using a mechanism similar to fatty acid synthase but with Coenzyme A instead of an acyl carrier protein. The video also notes that elongases do not introduce double bonds, which are added by desaturases.

What is the maximum number of carbons that fatty acid synthase can produce in a fatty acid?

• 14 carbons

• 18 carbons

• 16 carbons

• 12 carbons

Which enzyme complex is responsible for elongating fatty acids beyond 16 carbons?

• Desaturases

• Lipases

• Elongases

• Fatty acid synthase

Where is the enzyme complex elongases located within the cell?

• Golgi apparatus

• Mitochondria

• Smooth ER

• Nucleus

What is the key difference between the mechanisms of fatty acid synthase and elongases?

• Elongases use Coenzyme A instead of ACP

• Elongases use ATP instead of NADPH

• Elongases are located in the nucleus

• Elongases can add double bonds

Which molecule acts as the two-carbon donor in the elongation process?

• FADH2

• Acetyl CoA

• Malonyl CoA

• NADPH

Which enzymes are responsible for adding double bonds to fatty acids?

• Lipases

• Fatty acid synthase

• Desaturases

• Elongases

What is the primary function of elongases in fatty acid metabolism?

• To oxidize fatty acids

• To lengthen fatty acids

• To shorten fatty acids

• To add double bonds