MCQOPTIONS
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MCQOPTIONS
This section includes 73 Mcqs, each offering curated multiple-choice questions to sharpen your Life Sciences knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Which of the following does not occur during gluconeogenesis? |
| A. | The carboxylation of pyruvate to oxaloacetate |
| B. | The conversion of pyruvate to phosphoenolpyruvate (PEP) |
| C. | The decarboxylation of oxaloacetate to phosphoenolpyruvate |
| D. | The conversion of PEP to fructose bisphosphate |
| Answer» C. The decarboxylation of oxaloacetate to phosphoenolpyruvate | |
| 2. |
Saliva contains all of the following except |
| A. | hormones |
| B. | amylase |
| C. | bacteria-killing enzymes |
| D. | antibodies |
| Answer» B. amylase | |
| 3. |
What is present in the stomach to prevent self-digestion? |
| A. | Mucus |
| B. | acid |
| C. | Enzymes |
| D. | hormones |
| Answer» B. acid | |
| 4. |
The process not involved in the formation of glucose by gluconeo-genesis is |
| A. | the conversion of oxaloacetate to glucose |
| B. | the conversion of lactate to pyruvate |
| C. | the dephosphorylation of glucose-6-phosphate |
| D. | all of the above |
| Answer» B. the conversion of lactate to pyruvate | |
| 5. |
The conversion of pyruvate to lactate is catalysed by |
| A. | pyruvate carboxylase |
| B. | lactate dehydrogenase |
| C. | pyruvate dismutase |
| D. | pyruvate decarboxylase |
| Answer» C. pyruvate dismutase | |
| 6. |
Glucagon and epinephrine |
| A. | inhibits gluconeogenesis and stimulates glycolysis |
| B. | stimulates gluconeogenesis and glycolysis |
| C. | stimulates gluconeogenesis and inhibits glycolysis |
| D. | inhibits gluconeogenesis and glycolysis |
| Answer» D. inhibits gluconeogenesis and glycolysis | |
| 7. |
Insulin |
| A. | stimulates gluconeogenesis and glycolysis |
| B. | stimulates gluconeogenesis and inhibits glycolysis |
| C. | inhibits gluconeogenesis and glycolysis |
| D. | inhibits gluconeogenesis and stimulates glycolysis |
| Answer» E. | |
| 8. |
Which of the following enzymes plays an important role in the Cori " cycle? |
| A. | Glucokinase |
| B. | Glucose-6-phosphate dehydrogenase |
| C. | Lactate dehydrogenase |
| D. | Glucose isomerase |
| Answer» D. Glucose isomerase | |
| 9. |
Patients suffering from Von Gierke's disease are unable to perform gluconeogeneis because they have a defective |
| A. | lactate dehydrogenase |
| B. | glucose 6 phosphatase |
| C. | pyruvate carboxylase |
| D. | none of these |
| Answer» C. pyruvate carboxylase | |
| 10. |
The function of gluconeogenesis is |
| A. | maintenance of blood glucose levels during starvation or a low carbohydrate diet |
| B. | recovery of lactate from fermentation and glycerol from fat breakdown |
| C. | a pathway for the utilization of amino acids |
| D. | all of the above |
| Answer» E. | |
| 11. |
Which of the following can act as precursors for gluconeogenesis? |
| A. | Lactate |
| B. | Glycerol |
| C. | Alanine |
| D. | All of these |
| Answer» E. | |
| 12. |
The conversion of pyruvate to oxaloacetate |
| A. | requires biotin |
| B. | involves the fixation of carbon dioxide |
| C. | occurs in the mitochondria |
| D. | all of the above |
| Answer» B. involves the fixation of carbon dioxide | |
| 13. |
Pyruvate is initially converted to which of the following in the gluconeogenesis? |
| A. | Glycerol |
| B. | Phosphoenol pyruvate |
| C. | Oxaloacetate |
| D. | Acetyl CoA |
| Answer» D. Acetyl CoA | |
| 14. |
Fructose diphosphate accumulation would |
| A. | inhibit glycolysis and gluconeogenesis |
| B. | stimulate glycolysis and gluconeogenesis |
| C. | stimulate glycolysis and inhibit gluconeogenesis |
| D. | inhibit glycolysis and stimulate gluconeogenesis |
| Answer» D. inhibit glycolysis and stimulate gluconeogenesis | |
| 15. |
An intermediate which inhibits the activity of fructose 1,6 diphos-phatase would inhibit |
| A. | glycolysis |
| B. | pyrolysis |
| C. | gluconeogenesis |
| D. | none of these |
| Answer» D. none of these | |
| 16. |
Citric acid accumulation would |
| A. | stimulate phosphofructokinase activity |
| B. | stimulate fructose 1,6 diphosphatase activity |
| C. | inhibit phosphofructokinase activity |
| D. | both (b) and (c) |
| Answer» E. | |
| 17. |
Gluconeogenesis is the |
| A. | formation of glycogen |
| B. | breakdown of glucose to pyruvate |
| C. | breakdown of glycogen to glucose |
| D. | synthesis of glucose from non-carbohydrate precursors |
| Answer» E. | |
| 18. |
A catabolic intermediate which stimulates phosphofructokinase would stimulate |
| A. | gluconeogenesis |
| B. | glycolysis |
| C. | glycogen synthesis |
| D. | none of these |
| Answer» C. glycogen synthesis | |
| 19. |
Two major products of pentose phosphate pathway are |
| A. | nicotinamide adenine dinucleotide and ribose 5-phosphate |
| B. | flavine adenine dinuclueotide and glucose 5-phosphate |
| C. | FAD and CoA |
| D. | NADPH and NAD |
| Answer» B. flavine adenine dinuclueotide and glucose 5-phosphate | |
| 20. |
Glycogen degradation requires the enzyme namely |
| A. | glycogen phosphorylase and phosphoglucomutase |
| B. | glycogen phosphorylase and glycogen-debranching enzyme |
| C. | glycogen synthase and phosphorylase |
| D. | none of the above |
| Answer» C. glycogen synthase and phosphorylase | |
| 21. |
Gluconeogenesis uses |
| A. | 3 ATPs and 2 GTPs per glucose |
| B. | 2 ATPs and 1 GTPs per glucose |
| C. | 3 ATPs and 3 GTPs per glucose |
| D. | 4 ATPs and 2 GTPs per glucose |
| Answer» E. | |
| 22. |
Which of the following characteristic enzymes of gluconeogensis is not found in the cytosol? |
| A. | Pyruvate carboxlyase |
| B. | Fructose-l,6-bisphosphatase |
| C. | Both (a) and (b) |
| D. | Glucose-6-phosphatase |
| Answer» B. Fructose-l,6-bisphosphatase | |
| 23. |
During vigorous exercise, pyruvate produced by glycolysis is converted to |
| A. | acetate |
| B. | lactate |
| C. | monosodium phosphate |
| D. | pyruvic acid |
| Answer» C. monosodium phosphate | |
| 24. |
Hexokinase activity in glycolysis is inhibited by |
| A. | glucose 6- phosphate |
| B. | fructose 6-phosphate |
| C. | fructose 1,6 biphosphate |
| D. | phosphofructokinase |
| Answer» B. fructose 6-phosphate | |
| 25. |
Aldolases splits fructose 1,6 biphosphate into |
| A. | glyceraldehyde 3- phosphate |
| B. | glyceraldehyde 3- phosphate and dihydroxyacetone phosphate |
| C. | dihydroxyacetone phosphate |
| D. | none of the above |
| Answer» C. dihydroxyacetone phosphate | |
| 26. |
In the Glycolysis reaction, for each glucose conversion how many ATP's are produced? |
| A. | 4 |
| B. | 2 |
| C. | 1 |
| D. | 3 |
| Answer» C. 1 | |
| 27. |
Glycolysis reactions take place in |
| A. | cytoplasm |
| B. | cell membrane |
| C. | cell wall |
| D. | plasmids |
| Answer» B. cell membrane | |
| 28. |
Under aerobic condition pyruvate is converted by pyruvate dehydrogenase to |
| A. | phosphoenol pyruvate |
| B. | acetyl CoA |
| C. | lactate |
| D. | glyceraldehyde 3 phosphate |
| Answer» C. lactate | |
| 29. |
The hormones, glucagon and epinephrine, stimulate glycogen breakdown to G-6-P |
| A. | only in the liver |
| B. | using ATP as the phosphoryl donor |
| C. | directly, by binding to glycogen phosphorylase |
| D. | indirectly, by first stimulating adenylate cyclase to make cAMP |
| Answer» E. | |
| 30. |
Each reaction in a metabolic pathway is |
| A. | reversible |
| B. | irreversible |
| C. | catalyzed by a specific enzyme |
| D. | controlled by the end product |
| Answer» D. controlled by the end product | |
| 31. |
Regulated metabolic pathways are |
| A. | compartmentalized in eukaryotes |
| B. | usually regulated at the first step |
| C. | committed after the first step |
| D. | all of these |
| Answer» E. | |
| 32. |
In lysozyme catalysis, which of the following does not contribute? |
| A. | The abnormally high pKa of Glu35 |
| B. | The strained conformation of the D sugar |
| C. | Formation of a covalent intermediate at Asp52 |
| D. | Formation of a covalent intermediate at Ser195 |
| Answer» E. | |
| 33. |
The NAG6 substrate is hydrolyzed by human lysozyme to form |
| A. | 6 glucosamines + 6 acetic acids |
| B. | NAG4 + NAG2 |
| C. | NAG3 + NAG3 |
| D. | NAG3 |
| Answer» C. NAG3 + NAG3 | |
| 34. |
a-amylose is similar to |
| A. | β-sheets |
| B. | β-turned coils |
| C. | α-helices |
| D. | the hydrophobic core |
| Answer» D. the hydrophobic core | |
| 35. |
The sugar which forms major component of nucleic acids is |
| A. | ribose |
| B. | galactose |
| C. | mannose |
| D. | maltose |
| Answer» B. galactose | |
| 36. |
Storage polysaccharide made by animals is |
| A. | amylopectin |
| B. | glycogen |
| C. | cellulose |
| D. | collagen |
| Answer» C. cellulose | |
| 37. |
Cellulose fibers resemble with the protein structure in the form of |
| A. | β-sheets |
| B. | α-helices |
| C. | β-turns |
| D. | None of these |
| Answer» B. α-helices | |
| 38. |
The glycosidic bond |
| A. | in maltose is not hydrolyzed in lactose intolerant humans |
| B. | in sucrose is hydrolyzed by bees |
| C. | joins glucose and fructose to form sucrose |
| D. | both (b) and (c) |
| Answer» E. | |
| 39. |
Boat and chair conformations are found |
| A. | in pyranose sugars |
| B. | in any sugar without axial -OH groups |
| C. | in any sugar without equatorial -OH groups |
| D. | only in D-glucopyranose |
| Answer» B. in any sugar without axial -OH groups | |
| 40. |
When living organisms are cooled below some critical body temperature, the metabolic reactions within their cells cease to function properly. This malfunction occurs because |
| A. | their enzymes lose the proper three-dimensional shape |
| B. | enzyme active sites become permanently bound to substrates |
| C. | the activation energy for the reaction is raised |
| D. | there is insufficient molecular motion for substrates to interact |
| Answer» E. | |
| 41. |
What would be the molecular formula for a polymer made by linking ten glucose molecules together by dehydration synthesis, if molecular formula for glucose is C6H,206? |
| A. | C60H100O50 |
| B. | C60H120O60 |
| C. | C60H102O51 |
| D. | (C6H12O6)10 |
| Answer» D. (C6H12O6)10 | |
| 42. |
Which of the following would be considered a part of metabolism? |
| A. | Biosynthetic pathways that build DNA |
| B. | Catabolic pathways that break down complex carbohydrates |
| C. | The capture of light energy for use in making glucose |
| D. | All of the above |
| Answer» E. | |
| 43. |
The multistep pathways of metabolism are efficient because they |
| A. | locate all of the enzymes for a pathway in the same place within the cell |
| B. | use the same substrate for all of the enzymes in the pathway |
| C. | use the same enzyme for all of the substrates in the pathway |
| D. | spread the enzymes for a pathway into several different organelles |
| Answer» B. use the same substrate for all of the enzymes in the pathway | |
| 44. |
Which of the following is not involved in the biosynthesis of DNA? |
| A. | Energy from ATP |
| B. | Mononucleotides |
| C. | Carbonic anhydrase |
| D. | Enzymes |
| Answer» D. Enzymes | |
| 45. |
Which of the following statements about the energy needs of cells is false? |
| A. | Without a continuous input of energy, cell disorder will increase |
| B. | The laws of thermodynamics force cells to acquire energy |
| C. | Many cellular reactions have an associated activation energy |
| D. | The most usable energy for cells comes from the rapid combustion of glucose |
| Answer» E. | |
| 46. |
What is the consensus N-glycosylation site in a protein sequence? |
| A. | Asn-Xaa-(Ser or Thr) |
| B. | (Ser or Thr)-Asn-Ala |
| C. | Thr-(Asn or Gln)-Ala |
| D. | None of these |
| Answer» B. (Ser or Thr)-Asn-Ala | |
| 47. |
What is the cause of the genetic disease known as Galactosemia? |
| A. | Deficiency in lactase |
| B. | Absence of galactose 1-P uridyl transferase |
| C. | Absence of lactose synthetase |
| D. | Non functioning of semnase |
| Answer» C. Absence of lactose synthetase | |
| 48. |
Metabolic reactions that break down complex molecules into smaller compounds, thereby releasing usable energy for the cell, are best described as |
| A. | biosynthetic |
| B. | catabolic |
| C. | catalytic |
| D. | photosynthetic |
| Answer» C. catalytic | |
| 49. |
The ultimate source of energy that sustains living systems is |
| A. | glucose |
| B. | oxygen |
| C. | sunlight |
| D. | carbon dioxide |
| Answer» D. carbon dioxide | |
| 50. |
Name the major storage form of carbohydrates in animals? |
| A. | Cellulose |
| B. | Chitin |
| C. | Glycogen |
| D. | Starch |
| Answer» D. Starch | |