MCQ on Glycolysis & Gluconeogenesis
a) Glucokinase
b) Galactokinase
c) Galactose-1-Phosphate Uridyl transferase
d) UDP-Galactose 4- epimerase
2) Which of the following enzyme is defective in galactosemia (type I) - a fatal genetic disorder in infants?
a) Glucokinase
b) Galactokinase
c) Galactose-1-Phosphate Uridyl transferase
d) UDP-Galactose 4- epimerase
3) In the liver, the accumulation of which of the following metabolite attenuates the inhibitory of ATP on phosphofructokinase?
a) Glucose-6-Phosphate
b) Citrate
c) Fructose-1,6-Bisphosphate
d) Fructose-2,6-Bisphosphate
4) Mutation in which of the following enzymes leads to a glycogen storage disease known as "Tarui’s disease"?
a) Glucokinase
b) Phosphofructokinase
c) Phosphoglucomutase
d) Pyruvate Kinase
5) Erythrocytes undergo glycolysis for the production of ATP.
The deficiency of …………….................. enzyme leads to hemolytic anemia.
a) Glucokinase
b) Phosphofructokinase
c) Phosphoglucomutase
d) Pyruvate Kinase
6) Cancer cells have high energy demands for replication and division. Increased flux of glucose into glycolysis replenishes the energy demand.
2-c) Galactose-1-Phosphate uridyltransferase (GALT)
3-d) Fructose-2,6-Bisphosphate
5- d) Pyruvate Kinase
7- d) GLUT4
8- b) GLUT2
9- c) GLUT5
10- d) Alanine
11- d) during lactate formation, NADH is reconverted into NAD
12- b) Glucokinase
13- d) PFK-1 is regulated by posttranslational modification such as phosphorylation
14- b) Activated protein kinase A phosphorylates PFK-2 and activates the phosphatase domain
15-d) InsulinInsulin is a hormone produced by the pancreas that plays a central role in regulating blood sugar (glucose) levels and metabolism in the body. It is essential for maintaining glucose homeostasis and ensuring that cells receive the energy they need to function properly.
16-c) Glycolysis occurs in the presence and absence of oxygen
17- a) Hexokinase
18- b) 2 ATP
19- b) Conversion of glyceraldehydes-3-phosphate to 1-3-bisphosphoglycerate
20- b) Conversion of fructose-6-phosphate to fructose-1,6-bisphosphate
21- c) Glyceraldehyde-3-phosphate kinase
22-b) AMP
26-c) Liver
27-d) Acetyl CoA
28- a) Glucose-6-phosphatase
29-d) Acetyl CoA is an activator of enzyme pyruvate carboxylase
30- c) Defect in glucose-6-phosphatase leads to abnormal accumulation of glycogen in the liver
31-c) It involves the transport of lactate from skeletal muscle to the liver for gluconeogenesis.
32-b) Glucagon
a) Glucokinase
b) Phosphofructokinase
c) Phosphoglucomutase
d) Pyruvate Kinase
6) Cancer cells have high energy demands for replication and division. Increased flux of glucose into glycolysis replenishes the energy demand.
Which of the following enzyme plays an important role in tumor metabolism?
a) Glucokinase
b)Phosphofructokinase
c) Phosphoglucomutase
d) Pyruvate Kinase M2
7) Which of the following glucose transporter (GLUT) is important in insulin-dependent glucose uptake?
a) GLUT1
b) GLUT2
c) GLUT3
d) GLUT4
8) Which of the following glucose transporter (GLUT) is present in the beta cells of the pancreas?
a) GLUT1
b) GLUT2
c) GLUT3
d) GLUT4
9) Which of the following glucose transporter (GLUT) is important in fructose transport in the intestine?
a) GLUT1
b) GLUT3
c) GLUT5
d) GLUT7
10) Which of the following metabolite negatively regulates pyruvate kinase?
a) Fructose-1,6-Bisphosphate
b) Citrate
c) Acetyl CoA
d) Alanine
a) Glucokinase
b)Phosphofructokinase
c) Phosphoglucomutase
d) Pyruvate Kinase M2
7) Which of the following glucose transporter (GLUT) is important in insulin-dependent glucose uptake?
a) GLUT1
b) GLUT2
c) GLUT3
d) GLUT4
8) Which of the following glucose transporter (GLUT) is present in the beta cells of the pancreas?
a) GLUT1
b) GLUT2
c) GLUT3
d) GLUT4
9) Which of the following glucose transporter (GLUT) is important in fructose transport in the intestine?
a) GLUT1
b) GLUT3
c) GLUT5
d) GLUT7
10) Which of the following metabolite negatively regulates pyruvate kinase?
a) Fructose-1,6-Bisphosphate
b) Citrate
c) Acetyl CoA
d) Alanine
11) In absence of oxygen, pyruvate is converted into lactate in muscle because
a) Lactate is the substrate from the downstream pathway
b) Lactate acts as a substrate for the formation of amino acid
c) during the product of lactate two ATP are produced
d) during lactate formation, NADH is reconverted into NAD.
12) Which of the following glycolytic enzyme is inhibited by the accumulation of long-chain fatty acid in the liver?
a) Hexokinase
b) Glucokinase
c) Phosphofructokinase
d) Pyruvate kinase
13) Which of the following statement related to phosphofructokinase-I is false:
a) PFK-2 is the isoenzyme of PFK-1 that is present in the liver
b) PFK-1 is activated by AMP whereas inhibited by ATP and citrate
c) The binding of ATP to PFK-1 induces the conformation change from R to T state
d) PFK-1 is regulated by posttranslational modification such as phosphorylation
14) Which of the following statement about Phosphofructokinase-2 (PFK-2) is false?
a) PFK-2 is a bifunctional enzyme having a kinase domain, phosphatase domain, and a regulatory domain
b) Activated protein kinase A phosphorylates PFK-2 and activates the phosphatase domain
c) PFK-2 catalyzes the conversion of fructose-6-phosphate to fructose 2-6 bisphosphate
d) PFK-2 phosphatase activity is activated by the insulin signaling pathway.
15) Which of the following hormone helps in regulating blood sugar (glucose) levels and metabolism in the body, and promotes the uptake of glucose by cells, especially muscle, adipose (fat), and liver cells?
a) Lactate is the substrate from the downstream pathway
b) Lactate acts as a substrate for the formation of amino acid
c) during the product of lactate two ATP are produced
d) during lactate formation, NADH is reconverted into NAD.
12) Which of the following glycolytic enzyme is inhibited by the accumulation of long-chain fatty acid in the liver?
a) Hexokinase
b) Glucokinase
c) Phosphofructokinase
d) Pyruvate kinase
13) Which of the following statement related to phosphofructokinase-I is false:
a) PFK-2 is the isoenzyme of PFK-1 that is present in the liver
b) PFK-1 is activated by AMP whereas inhibited by ATP and citrate
c) The binding of ATP to PFK-1 induces the conformation change from R to T state
d) PFK-1 is regulated by posttranslational modification such as phosphorylation
14) Which of the following statement about Phosphofructokinase-2 (PFK-2) is false?
a) PFK-2 is a bifunctional enzyme having a kinase domain, phosphatase domain, and a regulatory domain
b) Activated protein kinase A phosphorylates PFK-2 and activates the phosphatase domain
c) PFK-2 catalyzes the conversion of fructose-6-phosphate to fructose 2-6 bisphosphate
d) PFK-2 phosphatase activity is activated by the insulin signaling pathway.
15) Which of the following hormone helps in regulating blood sugar (glucose) levels and metabolism in the body, and promotes the uptake of glucose by cells, especially muscle, adipose (fat), and liver cells?
a) Glucagon
b) Epinephrine
c) Cortisol
d) Insulin
16) Which of the following statement is true regarding glycolysis pathway?
a) Glycolysis occurs only in mammalian cells
b) Glycolysis occurs in mitochondria
c) Glycolysis occurs in the presence and absence of oxygen
d) Glycolysis occurs when ATP concentration is high.
17) What is the rate-limiting enzyme in glycolysis?
a) Hexokinase
b) Phosphohexose isomerase
c) Glyceraldehyde-3-phosphate dehydrogenase
d) Enolase
18) The net gain of adenosine triphosphate (ATP) during the conversion of glucose to pyruvate is:
b) Epinephrine
c) Cortisol
d) Insulin
16) Which of the following statement is true regarding glycolysis pathway?
a) Glycolysis occurs only in mammalian cells
b) Glycolysis occurs in mitochondria
c) Glycolysis occurs in the presence and absence of oxygen
d) Glycolysis occurs when ATP concentration is high.
17) What is the rate-limiting enzyme in glycolysis?
a) Hexokinase
b) Phosphohexose isomerase
c) Glyceraldehyde-3-phosphate dehydrogenase
d) Enolase
18) The net gain of adenosine triphosphate (ATP) during the conversion of glucose to pyruvate is:
a) 1 ATP
b) 2 ATP
c) 1 ATP +1 GTP
d) 4 ATP
19) During the conversion of glucose to pyruvate, two NADH molecules are generated.
b) 2 ATP
c) 1 ATP +1 GTP
d) 4 ATP
19) During the conversion of glucose to pyruvate, two NADH molecules are generated.
Which of the following steps generates NADH?
a) Conversion of fructose-6-phosphate to fructose-1-6-bisphosphate
b) Conversion of glyceraldehydes-3-phosphate to 1-3-bisphosphoglycerate
c)Conversion of 3-phosphoglycerate to 2-phosphoglycerate
d) Conversion of phosphoenolpyruvate to pyruvate
20) What is the committed step in glycolysis?
a) Conversion of glucose to glucose-6-phosphate
b) Conversion of fructose-6-phosphate to fructose-1,6-bisphosphate
c) Conversion of glyceraldehydes-3-phosphate to 1-3-bisphosphoglycerate
d) Conversion of 3-phosphoglycerate to 2-phosphoglycerate
21) Glycolysis consists of three irreversible steps.
a) Conversion of fructose-6-phosphate to fructose-1-6-bisphosphate
b) Conversion of glyceraldehydes-3-phosphate to 1-3-bisphosphoglycerate
c)Conversion of 3-phosphoglycerate to 2-phosphoglycerate
d) Conversion of phosphoenolpyruvate to pyruvate
20) What is the committed step in glycolysis?
a) Conversion of glucose to glucose-6-phosphate
b) Conversion of fructose-6-phosphate to fructose-1,6-bisphosphate
c) Conversion of glyceraldehydes-3-phosphate to 1-3-bisphosphoglycerate
d) Conversion of 3-phosphoglycerate to 2-phosphoglycerate
21) Glycolysis consists of three irreversible steps.
Which of the following enzyme-catalyzed reaction are not irreversible steps in glycolysis?
a) Hexokinase
b) Phosphofructokinase
c) Glyceraldehyde-3-phosphate kinase
d) Pyruvate kinase
22) All of the following are the negative regulators of phosphofructokinase(PFK) and can inhibit it's activity, except?
a) Adenosine triphosphate (ATP)
a) Hexokinase
b) Phosphofructokinase
c) Glyceraldehyde-3-phosphate kinase
d) Pyruvate kinase
22) All of the following are the negative regulators of phosphofructokinase(PFK) and can inhibit it's activity, except?
a) Adenosine triphosphate (ATP)
b) Adenosine monophosphate (AMP)
c) Citrate
d) pH
23) Which of the following enzyme is inhibited by sodium fluoride that is used as anticoagulant during blood collection and transport?
c) Citrate
d) pH
23) Which of the following enzyme is inhibited by sodium fluoride that is used as anticoagulant during blood collection and transport?
a) Glyceraldehyde-3-phosphate dehydrogenase
b) 3-phosphoglycerate mutase
c) Enolase
b) AMP
24) Which of the following step is inhibited during arsenate poisoning?
a) Glyceraldehyde-3-phosphate dehydrogenase
b) 3-phosphoglycerate mutase
c) Enolase
d) Pyruvate kinase
25)Which of the following enzyme catalyzes the conversion of pyruvate to lactate?
a) Pyruvate reductase
b) Lactate reductase
c) Lactate dehydrogenase
d) Pyruvate dehydrogenase
26) Glucokinase is an isoenzyme of hexokinase that has high Km (Michaelis constant) and Vmax (velocity) which means it has lower affinity for glucose and becomes active only when glucose levels are relatively high.
b) 3-phosphoglycerate mutase
c) Enolase
b) AMP
24) Which of the following step is inhibited during arsenate poisoning?
a) Glyceraldehyde-3-phosphate dehydrogenase
b) 3-phosphoglycerate mutase
c) Enolase
d) Pyruvate kinase
25)Which of the following enzyme catalyzes the conversion of pyruvate to lactate?
a) Pyruvate reductase
b) Lactate reductase
c) Lactate dehydrogenase
d) Pyruvate dehydrogenase
26) Glucokinase is an isoenzyme of hexokinase that has high Km (Michaelis constant) and Vmax (velocity) which means it has lower affinity for glucose and becomes active only when glucose levels are relatively high.
Which of the following organ expresses glucokinase?
a) Kidney
b) Muscle
c) Liver
d) Brain
27) Gluconeogenesis metabolic pathway is the synthesis of glucose from non-carbohydrate molecules.
a) Kidney
b) Muscle
c) Liver
d) Brain
27) Gluconeogenesis metabolic pathway is the synthesis of glucose from non-carbohydrate molecules.
Which of the following is not the substrate for gluconeogenesis?
a) Lactate
b) Alanine
c) Glycerol
d) Acetyl CoA (acetyl coenzyme A)
28) Gluconeogenesis occurs in the liver and kidneys.
a) Lactate
b) Alanine
c) Glycerol
d) Acetyl CoA (acetyl coenzyme A)
28) Gluconeogenesis occurs in the liver and kidneys.
Which is of the following enzyme are important for gluconeogenesis and are expressed exclusively in these tissues?
a) Glucose-6-phosphatase
b) Fructose-1,6-Bisphosphatase
c) Phosphoenolpyruvate carboxykinase
d) Pyruvate carboxylase
29) During gluconeogenesis, the three irreversible steps of glycolysis have to be bypassed. The first step is the conversion of pyruvate to phosphoenolpyruvate.
a) Glucose-6-phosphatase
b) Fructose-1,6-Bisphosphatase
c) Phosphoenolpyruvate carboxykinase
d) Pyruvate carboxylase
29) During gluconeogenesis, the three irreversible steps of glycolysis have to be bypassed. The first step is the conversion of pyruvate to phosphoenolpyruvate.
Which of the following statement is false regarding the reaction step?
a) This reaction involves a two-step process catalyzed by pyruvate carboxylase and phosphoenolpyruvate carboxykinase
b) Conversion of oxaloacetate from pyruvate occurs in mitochondria and shuttled into the cytosol.
c) Formation of phosphoenolpyruvate requires both ATP and GTP as an energy source.
d) Acetyl CoA is an activator of the enzyme pyruvate carboxylase.
30) During gluconeogenesis, the three irreversible steps of glycolysis have to be bypassed. The final step is the conversion of glucose-6-P to glucose which is catalyzed by glucose-6-phosphatase.
a) This reaction involves a two-step process catalyzed by pyruvate carboxylase and phosphoenolpyruvate carboxykinase
b) Conversion of oxaloacetate from pyruvate occurs in mitochondria and shuttled into the cytosol.
c) Formation of phosphoenolpyruvate requires both ATP and GTP as an energy source.
d) Acetyl CoA is an activator of the enzyme pyruvate carboxylase.
30) During gluconeogenesis, the three irreversible steps of glycolysis have to be bypassed. The final step is the conversion of glucose-6-P to glucose which is catalyzed by glucose-6-phosphatase.
Which of the following statement is true about the reaction step?
a) Conversion of glucose-6-phosphate to glucose releases one ATP molecule
b) It is a highly active enzyme in skeletal muscle
c) Defect in glucose-6-phosphatase leads to abnormal accumulation of glycogen in the liver
d) The reaction occurs in mitochondria
31) Which of the following statement is true about Cori Cycle?
a) The Cori cycle involves three tissues muscle, liver, and brain
b) It involves the transport of lactate from the liver to skeletal tissue for gluconeogenesis
c) It involves the transport of lactate from skeletal muscle to the liver for gluconeogenesis
d) It is active during resting stages and in well-fed condition
32) During prolong starvation, which of the following hormone is responsible for increasing gluconeogenesis in the liver?
a) Insulin
b) Glucagon
c) TSH
d) Thyroxine
Answers with Explanation:
a) Conversion of glucose-6-phosphate to glucose releases one ATP molecule
b) It is a highly active enzyme in skeletal muscle
c) Defect in glucose-6-phosphatase leads to abnormal accumulation of glycogen in the liver
d) The reaction occurs in mitochondria
31) Which of the following statement is true about Cori Cycle?
a) The Cori cycle involves three tissues muscle, liver, and brain
b) It involves the transport of lactate from the liver to skeletal tissue for gluconeogenesis
c) It involves the transport of lactate from skeletal muscle to the liver for gluconeogenesis
d) It is active during resting stages and in well-fed condition
32) During prolong starvation, which of the following hormone is responsible for increasing gluconeogenesis in the liver?
a) Insulin
b) Glucagon
c) TSH
d) Thyroxine
Answers with Explanation:
1-a) Glucokinase.
Glucokinase is an enzyme that plays a critical role in glucose metabolism by catalyzing the phosphorylation of glucose to form glucose-6-phosphate. It is primarily found in the liver and pancreatic beta cells.
2-c) Galactose-1-Phosphate uridyltransferase (GALT)
Galactosemia is a rare genetic disorder characterized by the inability of the body to properly metabolize galactose, a sugar found in milk and other dairy products. This condition is caused by mutations in genes that are responsible for producing enzymes involved in the breakdown of galactose. Type I galactosemia is the most common and severe form of galactosemia. Galactose-1-phosphate uridyltransferase (GALT), is required for converting galactose-1-phosphate into glucose-1-phosphate.
3-d) Fructose-2,6-Bisphosphate
Fructose 2,6-bisphosphate (Fru-2,6-BP) is a crucial regulatory molecule of glycolysis and gluconeogenesis metabolic pathways involved in glucose metabolism, it acts as an allosteric regulator of the key enzymes phosphofructokinase-1 (PFK-1) and fructose-1,6-bisphosphatase (FBPase-1).
4-b)Phosphofructokinase
Tarui's disease, also known as Glycogen Storage Disease Type VII (GSD VII) or Muscle Phosphofructokinase Deficiency, is a rare genetic disorder. It is caused by mutations in the gene that codes for the enzyme muscle phosphofructokinase (PFKM), which is essential for the glycolytic pathway.
5- d) Pyruvate Kinase
Pyruvate kinase (PK) deficiency is a genetic disorder that affects the glycolytic pathway, the deficiency of pyruvate kinase impairs the ability of red blood cells to generate sufficient ATP and maintain their structural integrity that leads to pyruvate kinase deficiency hemolytic anemia (PKDHA). Hemolytic anemia is the premature destruction of red blood cells (hemolysis), which can lead to a decrease in red blood cell count and anemia.
6- d) Pyruvate Kinase M2 (PKM2)
PKM2 is one of the four isoforms of pyruvate kinase involved in cellular metabolism. It is typically expressed during embryonic development and often found in cancer cells, provides energy and building blocks for rapid growth of cancer cells.
7- d) GLUT4
8- b) GLUT2
9- c) GLUT5
10- d) Alanine
11- d) during lactate formation, NADH is reconverted into NAD
12- b) Glucokinase
It has lower affinity for glucose and becomes active only when glucose levels are relatively high. The accumulation of long-chain fatty acid in the liver inhibits the enzyme glucokinase.
13- d) PFK-1 is regulated by posttranslational modification such as phosphorylation
14- b) Activated protein kinase A phosphorylates PFK-2 and activates the phosphatase domain
15-d) Insulin
16-c) Glycolysis occurs in the presence and absence of oxygen
Glycolysis serves as a critical energy-producing process in both aerobic (with oxygen) and anaerobic (without oxygen) conditions. Glycolysis is a fundamental metabolic pathway that takes place in the cytoplasm of cells and involves the breakdown of glucose into two molecules of pyruvate, along with the generation of a small amount of adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide (NADH).
17- a) Hexokinase
Hexokinase is an enzyme involved in the first step of glycolysis, the metabolic pathway that converts glucose into energy in cells.
18- b) 2 ATP
Two ATP molecules are produced during the glycolysis metabolic pathway (conversion of glucose to pyruvate)
19- b) Conversion of glyceraldehydes-3-phosphate to 1-3-bisphosphoglycerate
20- b) Conversion of fructose-6-phosphate to fructose-1,6-bisphosphate
21- c) Glyceraldehyde-3-phosphate kinase
22-b) AMP
Phosphofructokinase (PFK) is a key regulatory enzyme in glycolysis pathway. High levels of Adenosine triphosphate (ATP), Citrate and low pH (acidic) can inhibit the activity of PFK.
23- c) Enolase
It is an enzyme in the glycolytic pathway, sodium fluoride inhibits enolase and prevents glycolysis to occur during blood collection and transport, it enables accurate glucose measurement.
24-a) Glyceraldehyde-3-phosphate dehydrogenase
25- c) Lactate dehydrogenase
25- c) Lactate dehydrogenase
26-c) Liver
Glucokinase is primarily found in the liver and pancreatic beta cells. In the liver, glucokinase is a crucial component of glucose regulation and helps regulate glucose homeostasis in the body.
27-d) Acetyl CoA
Acetyl CoA is not a substrate for gluconeogenesis because the conversion of pyruvate to acetyl CoA is an irreversible step that is catalyzed by the enzyme pyruvate dehydrogenase.
28- a) Glucose-6-phosphatase
29-d) Acetyl CoA is an activator of enzyme pyruvate carboxylase
30- c) Defect in glucose-6-phosphatase leads to abnormal accumulation of glycogen in the liver
31-c) It involves the transport of lactate from skeletal muscle to the liver for gluconeogenesis.
Cori cycle is also known as lactic acid cycle. It allows lactate, which is produced as a byproduct of anaerobic metabolism in muscle cells, to be recycled back into glucose in the liver, which can then be used as a fuel source by various tissues, including muscles, brain, and red blood cells (bloodstream).
32-b) Glucagon