Complete Study Guide: TAG Digestion, Transport, Mobilization, and Ketone Bodies

These flashcards cover the key concepts related to TAG digestion, transport, mobilization, β-oxidation, and ketone bodies, assisting in understanding their roles and mechanisms in metabolism.

What is the role of bile salts in TAG digestion?

Bile salts emulsify dietary fats.

What enzyme converts TAG into MAG and fatty acids?

Lipases convert TAG into MAG and fatty acids.

What structure transports TAG via the lymph to the blood?

Chylomicrons transport TAG via lymph to blood.

What are the main components of chylomicrons?

Chylomicrons are composed of TAG, cholesterol esters, phospholipids, and apolipoproteins.

What triggers the mobilization of TAG?

Glucagon and epinephrine trigger TAG mobilization.

What is the function of lipoprotein lipase?

Lipoprotein lipase releases fatty acids to tissues.

How is fatty acid released during TAG mobilization?

PKA activates hormone-sensitive lipase (HSL) and perilipin, leading to the release of fatty acids and glycerol.

What is required for the activation of the β-oxidation pathway?

Acyl-CoA synthetase activates the pathway at a cost of 2 ATP equivalents.

What is the product of the β-oxidation of palmitate after 7 cycles?

Total energy yield includes 7 NADH and 7 FADH2, plus 24 NADH, 8 FADH2, and 8 GTP from TCA.

What is the process for glycerol metabolism?

Glycerol is phosphorylated to G3P by glycerol kinase, then converted to DHAP by G3P dehydrogenase.

What enzyme catalyzes the synthesis of ketone bodies from two AcCoA?

Thiolase catalyzes the conversion of 2 AcCoA to acetoacetyl-CoA.

What are ketone bodies used for in the body?

They serve as fuel for the brain and muscle during periods of glucose shortage.

What metabolic state leads to the production of ketone bodies?

Ketone bodies are produced during fasting, starvation, and diabetes.

Why are ketones produced only when glucose is low?

Low insulin and high glucagon levels lead to lipolysis and increased β-oxidation, causing excess AcCoA which promotes ketogenesis.

What is acetone and how is it produced?

Acetone is formed by spontaneous decarboxylation of acetoacetate.

What indicates ketosis in a patient with diabetes?

Acetone breath indicates the presence of ketosis.

How does the regulation of TAG storage differ from its mobilization?

TAG storage is influenced by insulin, while mobilization is influenced by glucagon.

What do β-oxidation and TCA have in common?

They share similar reaction logic in their metabolic pathways.

Where does fatty acid oxidation occur relative to fatty acid synthesis?

Fatty acid oxidation occurs in mitochondria using NAD+/FAD, while fatty acid synthesis occurs in the cytosol using NADPH.