Fatty Acid Catabolism

These flashcards cover key concepts related to fatty acid catabolism, including digestion, transport, mobilization, oxidation, and ketone body synthesis and utilization.

What are the main functions of fats in biological systems?

Fats serve as components of membranes, energy storage, and signaling molecules.

How are fatty acids numbered?

Carbons are numbered from the carboxylic acid group, with the β carbon in position 3, while ω numbering occurs from the opposite end.

What happens to triacylglycerides (TAGs) during digestion?

TAGs break down into 3 fatty acids and 1 glycerol.

What is the purpose of bile salts during fat digestion?

Bile salts are released from the gallbladder to emulsify fats in the small intestine.

What is a chylomicron?

A chylomicron is a mix of fats, carrier proteins, phospholipids, and cholesterol that transports absorbed fats through the lymphatic system.

What happens to fatty acids in adipose tissue?

Fatty acids are converted back to TAGs and stored as lipid droplets.

Where are fatty acids used to provide energy for gluconeogenesis?

In the liver.

How are fatty acids activated for β-oxidation?

Fatty acids are activated by CoA-SH to form acyl-CoA.

What is the principal remaining product after β-oxidation?

Acetyl-CoA can enter the TCA cycle.

How does the body mobilize stored fats?

Signaled by hormones such as epinephrine or glucagon, lipases break down TAGs into fatty acids and glycerol.

What is the role of NAD+/NADH and FAD/FADH2 during fatty acid oxidation?

NAD+ and FAD are used for oxidation, with their reduced forms providing energy for the electron transport chain.

What modifications occur to unsaturated fatty acids during β-oxidation?

Cis double bonds are converted to trans double bonds by an isomerase.

What additional steps are required for the oxidation of odd-numbered fatty acids?

One carbon must be added, and other reactions convert the molecule into propionyl-CoA.

Where does the processing of branched fatty acids occur?

Processing of branched fatty acids occurs in peroxisomes.

What is the significance of ketone bodies during fatty acid catabolism?

Ketone bodies are formed when Acetyl-CoA is shunted to provide energy when glucose is in short supply.

How are acetoacetate and D-β-hydroxybutyrate utilized for energy?

These ketone bodies enter the TCA cycle as Acetyl-CoA.