Lecture 5

Question 1

· Name the functions of lipids

Answer 1

Lipids are found in the cell membrane, plays an important role in cell signaling and is used to store energy.

Question 2

· Describe the basic structure of triacylglycerol

Answer 2

They are fatty acid esters of glycerol

Question 3

· Describe the key steps in fatty acid oxidation, and where they occur

Answer 3

Fatty acid oxidation occurs in the mitochondria and it breaks down one CH2 at a time with thiolysis (HS-CoA). Four repeatable reactions generate FADH2, NADH and acetylCoA. B-oxidation occurs at the B carbon of the fatty acid. There are four steps in fatty acid oxidation, oxidation, hydration, oxidation, thiolysis.

Question 4

· Describe what happens to excess acetyl-CoA

Answer 4

They are turned into ketone bodies.

Question 5

· Name the key enzymes in fatty acid synthesis, and where they can be found

Answer 5

Acetyl-CoA carboxylase catalyzes the commitment step in fatty acid synthesis. Fatty acid synthase catalyzes a series of reactions by adding two carbons to a growing fatty acid chain.