4th Biochesmitry Lecture Exam (Batch 2026) Flashcards
- True of the Pentose Phosphate Pathway:
A.Occurs in the cytoplasm
B.Has three irreversible reactions
C.Produces ATP
D.Produces Ribose
D.Produces Ribose
- Coenzyme responsible for the dehydrogenation of Glucose 6 Phophate:
A.NADP+
B.NADPH
C.NADP+ and NADPH
D.NAD
A.NADP+
- Ribulose 5 Phosphate is an important product of Pentose Phosphate Pathway because:
A.it is a substrate for fatty acid synthesis
B.It is a substrate for steroid sythesis
C.It is a substrate for nucleotide synthesis
D.all of the above
C.It is a substrate for nucleotide synthesis
- The products of the Pentose Phosphate Pathway are:
A.2 NADPH, 1 carbon dioxide, 2 Ribose
B.2 NADPH, 1 carbon dioxide, Ribose
C.2 NADPH, 2 carbon dioxide, Ribose
D.1 NADPH, 2 carbon dioxide, 2 Ribose
B.2 NADPH, 1 carbon dioxide, Ribose
- Substances that may make people with G6PD symptomatic
A.Fava beans
B.Anti Tuberculosis drugs
C.Anti-lnflammatories
D.All of the above
A.Fava beans
- True about G6PD
A.characterized by hemolytic anemia
B.does not affect life expectancy
C.Common in MiddIe America, Europe, and Africa
D.symptomatic
A.characterized by hemolytic anemia
- G6PD is most severe in RBC’s because:
A.The Pentose Phosphate Pathway is the sole source of NADPH in RBC’s
B.RBC’s have nucleus and can produce ribuIose-5-phosphate
C.Nore NADPH is needed in RBC’s to reduce glutathione
D.Glucose-6-Phosphate is consumed in RBC’s
A.The Pentose Phosphate Pathway is the sole source of NADPH in RBC’s
- A medical student developed hemolytic anemia after taking the oxidizing malarial drug primaquine. This severe reaction is most likely due to:
A.Glucose 6 phosphate dehydrogenase deficiency
B.Scurvy
C.Diabetes
D.Glycogen phosphorylase activity
A.Glucose 6 phosphate dehydrogenase deficiency
- Familial fructokinase deficiency causes no symptoms because:
A.hexokinase can phosphorylate fructose
B.liver aldolase can metabolize it
C.excess fructose is excreted trough feces
D.excess fructose is converted to glucose
A.hexokinase can phosphorylate fructose
10.The Uronic Acid Pathway: ,
A.catalyzes conversion of glucose to glucoronic, pentoses, sialic acid
B.Energy producing reaction
C.Occurs in the cytosol
D.alternative pathway for the oxidation of glucose
D.alternative pathway for the oxidation of glucose
- Which of the following statements about the metabolism of fructose is NOT true?
A.it can bypass phospofructokinase 1
B.it is inhibited by excess glucose
C.fructokinase needs magnesium as a cofactor
D.it ultimately produces glyceraldehyde 3-phosphate and dihydroacetone phosphate
B.it is inhibited by excess glucose
- Which statement regarding the reaction catalyzed by glucose 6-phosphate dehydrogenase is true?
A.it produces acetyl coA
B.it is the rate limiting step of the citric acid cycle
C.it produces NADP
D.it is the rate limiting step of the pentose phosphate pathway
D.it is the rate limiting step of the pentose phosphate pathway
- Which statement regarding transaldolase is true?
A.it links the pentose phosphate pathway to the citric acid cycle
B.it is an enzyme of the non oxidative phase of the pentose phosphate pathway
C.it requires thiamine pyrophosphate
D.it catalyzes the transfer of 2 carbon units
B.it is an enzyme of the non oxidative phase of the pentose phosphate pathway
- Which of the following is associated correctly?
A.maltose: galactose and glucose
B.sucrose: glucose and galactose
C.lactose: glucose and glucose
D.sucrose: glucose and fructose
E.lactose: galactose and galactose
D.sucrose: glucose and fructose
- Which of the following enxymes is NOT matched correctly to the reaction it catalyzes?
A.Lactase: Lactose: glucose and galactose
B.Galactose 1-Phophate uridyltransferase: galctose 1-Phosphate and UDP glucose to UDP-gaIactose and glucose 1-Phosphate
C.Galactose 1-Phophate uridyItransferase:glucose 6-phosphate and GDP Glucose
D.UDP gaIactose-4-epimerase:UDP-gaIactose to UDP-glucose
C.Galactose 1-Phophate uridyItransferase:glucose 6-phosphate and GDP Glucose
- Which statement regarding the pentose phosphate pathway is true?
A.it participates in the synthesis of NADP
B.it is regulated by the products of the citric acid cycle
C.it has multiple points of entry and endpoints connected to other pathways
D.it has multiple inputs but only 1 output
E.It is involved in the oxidation of fatty acids
C.it has multiple points of entry and endpoints connected to other pathways
- Salla disease is a rare disease resulting from the accumulation of:
A.fructose
B.hexosaminase
C.sialic acid
D.folinic acid
C.sialic acid
- Mannose can enter the glycolytic pathway through the:
A.isomerization into fructose 6-Phosphate
B.isomerization of glyceraldehyde 3-phosphate
C.it is a substrate of the glycolytic pathway
D.Through xyIuIose-5-Phospate being converted to Fructose 6-phosphate
A.isomerization into fructose 6-Phosphate
- Which enzyme-substance demonstrates the correct pairing?
A.galactokinase deficiency leads to accumulation of galactose 1-Phosphate
B.Aldose reductase leads to accumulation of galactitol
C.GALT deficiency leads to accumulation of galactose
D.A and C only
E.all of the above
B.Aldose reductase leads to accumulation of galactitol
- Which is true regarding fructose metabolism?
A.The affinity of hexokinase for Fructose 6-Phospate is higher than fructose
B.Can be catalyzed by Aldolase A B and C
C.A deficiency in Aldolase B can cause fructose poisoning
D.A and C only
E.all of the above
D.A and C only
- Which among the following is true reqarding phosphofru4okinase 1? {/^„)
A.catalyses the rate limiting step for glycolysis
B.catalyses synthesis of fructose 2 6-bisphosphate from fructose 6 -phosphate
C.is bypassed in fructose metabolism
D.A and C only
E.all of the above
D.A and C only
- In essential pentosuria, there is accumulation of what substance in the urine?
A.xylulose
B.lactose
C.fructose
D.galactose
E.fucose
A.xylulose
- Which is true regarding the Uronic Acid Pathway?
A.L-GuIonate is converted from UDP-gIucoronate
B.ascorbic acid cannot be synthesized in some animals
C.L-GuIonate is reduced
D.A and B only
E.all of the above
D.A and B only
- Which among the following demonstrate the use of NADPH?
A.Reduces Hydrogen Peroxide
B.Preserve integrity of WBC membrane
C.Phacgocytosis by red blood cells
D.A and C only
E.all of the above
A.Reduces Hydrogen Peroxide