Fatty Acid and Triacylglycerol Metabolism Flashcards
What is the primary storage site for fatty acids in the body?
a) Liver
b) Muscle tissue
c) Adipose tissue
d) Bone marrow
c) Adipose tissue
What are the major physiological roles of fatty acids?
a) Fatty acids are primarily used as enzymes in metabolic pathways.
b) Fatty acids are structural components of carbohydrates.
c) Fatty acids serve as building blocks of proteins.
d) Fatty acids serve as fuel molecules, building blocks of phospholipids and glycolipids, targets for protein modification, and hormone and intracellular messenger precursors.
d) Fatty acids serve as fuel molecules, building blocks of phospholipids and glycolipids, targets for protein modification, and hormone and intracellular messenger precursors.
Which role do fatty acids play in the modification of proteins?
a) They serve as cofactors for enzyme reactions.
b) They serve as structural elements in protein folding.
c) They are attached covalently to proteins to target them to membrane locations.
d) They act as signaling molecules for protein synthesis.
c) They are attached covalently to proteins to target them to membrane locations.
How do fatty acid derivatives function in hormone and intracellular signaling?
a) They bind to DNA to regulate gene expression.
b) They directly activate enzymes involved in cellular metabolism.
c) They interact with cell surface receptors to initiate signaling cascades.
d) They transport ions across cell membranes.
c) They interact with cell surface receptors to initiate signaling cascades.
Where is white adipose tissue primarily located in the body?
a) Only in the liver
b) Only in muscles
c) Under the skin and surrounding internal organs
d) Only in the brain
c) Under the skin and surrounding internal organs
What is the major function of adipocytes?
a) Synthesis of cholesterol
b) Synthesis of glucose
c) Accumulation and storage of triacylglycerols
d) Synthesis of proteins
c) Accumulation and storage of triacylglycerols
What is the main role of adipose tissue in metabolism?
a) Breakdown of carbohydrates
b) Synthesis of nucleic acids
c) Storage and mobilization of triacylglycerols into fuel
d) Transport of oxygen
c) Storage and mobilization of triacylglycerols into fuel
What is an intracellular lipid droplet specialized for?
a) Synthesis of proteins
b) Synthesis of carbohydrates
c) Synthesis of phospholipids
d) Storage of triacylglycerols
d) Storage of triacylglycerols
How are ingested triacylglycerides degraded during dietary fat digestion?
a) By proteases
b) By lipases
c) By carbohydrases
d) By nucleases
b) By lipases
What is the role of bile salts during dietary fat digestion?
a) They act as enzymes to break down fats.
b) They emulsify triacylglycerides to make them accessible to lipases.
c) They transport fatty acids across the intestinal membrane.
d) They convert triacylglycerides into chylomicrons.
b) They emulsify triacylglycerides to make them accessible to lipases.
In what orientation is the glycerol head group of triacylglycerides positioned during digestion?
a) Toward the lipid bilayer
b) Toward the lumen of the intestines
c) Toward the bloodstream
d) Toward the aqueous environment where lipase resides
d) Toward the aqueous environment where lipase resides
What happens to triacylglycerides when they cross the intestines?
a) They are degraded into fatty acids and glycerol.
b) They are reformed.
c) They are converted into chylomicrons.
d) They are transported to the liver.
b) They are reformed.
How are triacylglycerides transported to adipose tissues after digestion?
a) Through the bloodstream
b) Through the lymphatic system within chylomicrons
c) Through the nervous system
d) Through the digestive system within bile salts
b) Through the lymphatic system within chylomicrons
What is the first stage required for the use of fatty acids as fuel?
a) Mobilization of lipids through phospholipid degradation
b) Activation of fatty acids in the mitochondria
c) Mobilization of lipids through triacylglycerol degradation
d) Transport of lipids to the liver
c) Mobilization of lipids through triacylglycerol degradation
What is involved in the second stage of processing fatty acids as fuel?
a) Degradation of fatty acids to acetyl CoA
b) Mobilization of lipids through triacylglycerol degradation
c) Activation of the fatty acids and transport into the mitochondria
d) Conversion of fatty acids into glucose
c) Activation of the fatty acids and transport into the mitochondria
What is the final stage in the processing of fatty acids for fuel utilization?
a) Mobilization of lipids through triacylglycerol degradation
b) Activation of fatty acids in the mitochondria
c) Degradation of fatty acids to acetyl CoA for processing in the citric acid cycle
d) Transport of lipids into the adipose tissue
c) Degradation of fatty acids to acetyl CoA for processing in the citric acid cycle
Which stage involves the degradation of fatty acids to acetyl CoA?
a) Stage 1 (mobilization)
b) Stage 2 (activation and transport)
c) Stage 3 (breakdown into acetyl CoA)
d) None of the above
c) Stage 3 (breakdown into acetyl CoA)
What occurs during Stage 1 of the processing of fatty acids as fuel?
a) Degradation of fatty acids to acetyl CoA
b) Mobilization of lipids, release from adipose tissue, and transport to energy-requiring tissues
c) Activation of fatty acids and transport into the mitochondria
d) Synthesis of triacylglycerols
b) Mobilization of lipids, release from adipose tissue, and transport to energy-requiring tissues
What catalyzes the hydrolysis of triacylglycerols to fatty acids during mobilization?
a) Hormones
b) Perilipin
c) Hormonally controlled lipases
d) Phosphorylation
c) Hormonally controlled lipases
Which proteins are phosphorylated by PKA upon activation of the 7TM receptor?
a) Perilipin and hormone-sensitive lipase
b) Phospholipase A2 and phosphatidic acid phosphatase
c) Apolipoprotein B-48 and chylomicrons
d) Sphingomyelinase and ceramide
a) Perilipin and hormone-sensitive lipase
What is the first step in the conversion of triacylglycerols into free fatty acids in response to hormonal signals?
a) Activation of protein kinase A
b) Phosphorylation of perilipin
c) Conversion of diacylglycerol into triacylglycerol
d) Release of monoacylglycerol
a) Activation of protein kinase A
What does protein kinase A phosphorylate in the process?
a) ATGL
b) Perilipin
c) Hormone-sensitive lipase
d) Monoacylglycerol lipase
b) Perilipin
What is the role of ATGL in the process?
a) It converts triacylglycerol into diacylglycerol.
b) It releases a fatty acid from diacylglycerol.
c) It completes the mobilization process.
d) It phosphorylates perilipin.
a) It converts triacylglycerol into diacylglycerol.
What is the product of the action of hormone-sensitive lipase on diacylglycerol?
a) Triacylglycerol
b) Monoacylglycerol
c) Fatty acid
d) Phosphatidic acid
c) Fatty acid