Tutorial Practice Questions - Week 11 - Foundations of Metabolism Flashcards
Which sentence is incorrect about fatty acid beta-oxidation ?
a. It involves sequential rounds of 4 reactions
b. Each round of 4 reactions produces: 1 acetyl-CoA, 1 NADH and 1 FADH2
c. It requires activation of the fatty acid with CoA, so it can be transported into
the mitochondrial matrix
d. Acetyl-CoA generated from fatty acid oxidation cannot enter the TCA cycle
because the TCA cycle occurs in the cytoplasm
d
Which sentence is correct about fatty acid beta-oxidation and fatty acid biosynthesis?
a. Fatty acid beta-oxidation occurs in the cytoplasm and fatty acid biosynthesis
occurs in the mitochondrial matrix
b. Fatty acid beta-oxidation transfer electrons to NAD+ and FAD, whereas fatty
acid synthesis uses NADPH as electron donor.
c. The acyl carrier protein is bound to acyl- in beta-oxidation, malonyl-CoA is
required to initiate fatty acid biosynthesis
d. Insulin stimulates fatty acid degradation and inhibits fatty acid biosynthesis.
e. High levels of ATP stimulate beta-oxidation and inhibit fatty acid biosynthesis.
b
How many rounds of fatty acid beta-oxidation are required to degrade a C18:0 fatty acid?
8
How many Acetyl-CoA, NADH and FADH2 molecules are obtained during the beta-oxidation of C18:0?
9 Acetyl-CoA, 8 NADH, 8 FADH2
What is the effect of glucagon in the FA metabolism?
Glucagon is a hormone that is released when there is low sugar concentration. It activates FA mobilization from adipocytes, so FAs can be degraded and used as a source of ATP. This strategy saves glucose from being used as fuel.
Insulin counteracts high glucose concentration in the blood. How insulin regulates
carbohydrate and FA metabolism?
Insulin is released when there is high sugar concentration. It stimulates the synthesis of
enzymes that activate glycolysis in some tissues, glycogen synthesis and FA synthesis in others
