QUESTIONS & ANSWERS(RATED A+)
All of the compounds represent different metabolites of pyruvate except:
A. Acetyl-CoA
B. Alanine
C. Glutamate
D. Lactate
E. Oxaloacetate - ANSWERC. Glutamate
Signal transduction involving glucagon has which of the following as a second
messenger?
A. Ca^2+
B. cAMP
C. cGMP
D. calmodulin
E. inositol triphosphate (IP3) - ANSWERB. cAMP
The key regulatory enzymes that commit the cell to either glycolysis or gluconeogenesis
are PFK-1 and FBPase-1. Which molecule is the key allosteric effector of the
PFK-1/FBPase-1 enzyme system?
A. Glucose
B. Glucose-6-phosphate (G6P)
C. Fructose-6-phosphate (F6P)
D. Fructose-1,6-biphosphate (FBP)
E. Fructose-2,6-biphosphate (F2,6P) - ANSWERE. F2,6P
Which is not required for the oxidative decarboxylation of pyruvate to form acetyl-CoA
by the pyruvate dehydrogenase complex?
A. NAD+
B. FADH2
C. Lipoic acid
D. Coenzyme A
E. Thiamine Pyrophosphate (TPP) - ANSWERB. FADH2
As glucose levels in the blood begin to drop, glucagon is released from the alpha cells
of the pancreas. Release of this polypeptide hormone helps increase the availability of
ATP-producing compound by
A. inhibiting acetyl-Coa carboxylase causing an increased in beta-oxidation
, B. stimulating glycogen phophorylase causing the release of glucose from glycogen
C. stimulating hormone-sensitive triacylglycerol lipase in adipose cells causing the
release of fatty acids
D. all of the above
E. none of the above - ANSWERD. all of the above
During starvation or diabetes mellitus the brain derives most of its energy from
A. fatty acids
B. glucose
C. ketone bodies
D. glycogen
E. fructose - ANSWERC. ketone bodies
Which receptor has inherent tyrosine kinase activity?
A. Epinephrine receptor
B. G protein receptor
C. Glucagon receptor
D. Insulin receptor
E. Testosterone receptor - ANSWERD. Insulin receptor
Which statement is correct concerning the pentose phosphate pathway?
A. It requires NAD+
B. It reduces G6P in the first step
C. It provides precursors for the synthesis of nucleotides
D. It is necessary for maintaining oxidized glutathione (GSSG)
E. It generates 2 moles of ATP for every mole of glucose consumed - ANSWERC. It
provides precursors for the synthesis of nucleotides
Ribose-5-phosphate(R5P)
All of these enzymes in the TCA cycle require NAD+ except
A. Malate dehydrogenase
B. Succinate dehydrogenase
C. Isocitrate dehydrogenase
D. alpha-ketoglutarate dehydrogenase
E. All of the above require NAD+ - ANSWERB. Succinate dehydrogenase
Generates ubiquitol
The common intermediate metabolite of the urea and TCA cycle is
A. Arginine