Biochem #22
How many molecules of acetyl CoA are needed for laurate (12:0) synthesis?
6
What inhibits acetyl CoA carboxylase 1 and subsequently inhibits fatty acid synthesis?
AMP-activated protein kinase
Linoleate (18:2 cis-Δ9, Δ12) and linolenate (18:3 cis-Δ9, Δ12, Δ15) are essential fatty acids for mammals because mammals cannot synthesize fatty acids with double bonds at carbon atoms beyond _______ in the fatty acid chain.
C-9
What compound is formed by acetoacetate oxidation with NADH consumption?
D-3-hydroxybutyrate
How many energy-rich molecules are formed after b-oxidation of butyryl CoA (C3H7CO~SKoA)?
FADH2 + NADH + 2 acetyl CoA
Which reaction product is formed after hydration of trans-Δ2-enoyl CoA by crotonase?
L-3-hydroxyacyl CoA
Which enzyme catalyzes the formation of 3-ketoacyl CoA in the β-oxidation pathway?
L-3-hydroxyacyl CoA dehydrogenase
What supplies the reductive power for fatty acid synthesis?
NADPH
What is the preferable fuel for heart muscle and the renal cortex?
acetoacetate
What source of fuel energy is used by the brain instead of glucose under starvation conditions?
acetoacetate
Which ketone body is formed from acetyl CoA in three reactions catalyzed sequentially by 3-ketothiolase, hydroxymethylglutaryl CoA synthase, and hydroxymethylglutaryl CoA cleavage enzyme?
acetoacetate
What is the reaction product of the condensation of acetyl ACP and malonyl ACP in fatty acid synthesis in bacteria?
acetoacetyl ACP
Which reaction product is formed from acetoacetate in reactions catalyzed by a specific CoA transferase and thiolase during utilization of acetoacetate as a fuel?
acetyl CoA
What catalyzes the formation of malonyl CoA in fatty acid synthesis?
acetyl CoA carboxylase
What catalyzes the formation of acetyl ACP in fatty acid synthesis?
acetyl transacylase
Which enzyme includes several isozymes having different chain-length specificity?
acyl CoA dehydrogenase
Which is the coenzyme of propionyl CoA carboxylase?
biotin
Which molecule is formed in the end of the first elongation cycle of fatty acid synthesis?
butyryl ACP
What stimulates the breakdown of triacylglycerols by phosphorylation of perilipin and activation of a hormone-sensitive lipase in adipose tissue?
c. glucagon
What inhibits carnitine acyltransferase I and, accordingly, blocks the entry of fatty acyl CoAs into the mitochondrial matrix when they are abundant?
c. malonyl CoA
What molecule is used to transport acetyl groups from the mitochondrial matrix to the cytoplasm?
citrate
What activates fatty acid synthesis?
d. citrate
What catalyzes the formation of butyryl ACP from crotonyl ACP in fatty acid synthesis?
enoyl reductase
What compounds do fatty acids use as building blocks?
glycolipids and phospholipids
Where does fatty acid synthesis take place?
in cytoplasm
Where does oxidation of long-chain and branched fatty acids take place?
in peroxisomes
Which are enzymes that digest triacylglycerols into free fatty acids and monoacylglycerol?
lipases
The committed step in fatty acid synthesis is the formation of:
malonyl CoA.
What catalyzes the formation of malonyl ACP in fatty acid synthesis?
malonyl transacylase
Which reaction in the β-oxidation pathway yields NADH?
oxidation of L-3-hydroxyacyl CoA
Which reaction in the β-oxidation pathway yields FADH2?
oxidation of acyl CoA
What is the major product of the fatty acid synthase in animals?
palmitate
The synthesis of fatty acids with an odd number of carbon atoms starts with:
propionyl ACP, which is formed from propionyl CoA.
Which enzyme determines fatty acid chain length in fatty acid synthesis?
thioesterase
What catalyzes the formation of D-3-hydroxybutyryl ACP from acetoacetyl ACP in fatty acid synthesis?
β-ketoacyl reductase
Which enzyme catalyzes the cleavage of 3-ketoacyl CoA in fatty acid oxidation?
β-ketothiolase
What pathway degrades an acyl CoA into acetyl CoA?
β-oxidation
How many carbon atoms are there in the fatty acid chain shortened in one round of fatty acid oxidation?
2
How many energy-rich molecules are needed for one elongation cycle of fatty acid synthesis?
2 NADH
Which enzyme needs NADPH in β-oxidation of unsaturated fatty acids?
2,4-dienoyl CoA reductase
