MCQOPTIONS
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MCQOPTIONS
This section includes 58 Mcqs, each offering curated multiple-choice questions to sharpen your Biochemistry knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
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. | |
| 2. |
Which of the following is carried out when cAMP functions as a second messenger? |
| A. | Acts second in importance to AMP |
| B. | Activates all cytosolic protein kinases |
| C. | Activates the cAMP-dependent protein kinase |
| D. | Acts outside the cell to influence cellular processes |
| Answer» D. Acts outside the cell to influence cellular processes | |
| 3. |
The cells dependent solely on glucose as an energy source are |
| A. | muscle cells |
| B. | brain cells |
| C. | kidney cells |
| D. | liver cells |
| Answer» C. kidney cells | |
| 4. |
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. | |
| 5. |
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. | |
| 6. |
Gluconeogenesis requires a higher amount of ATP equivalents as compared to that produced by glycolysis because |
| A. | gluconeogenesis releases energy as heat |
| B. | glycolysis releases energy as heat |
| C. | glycolysis occurs in the mitochondria while gluconeogenesis occurs in the cytosol |
| D. | all of the above |
| Answer» C. glycolysis occurs in the mitochondria while gluconeogenesis occurs in the cytosol | |
| 7. |
During vigorous exercise, pyruvate produced by glycolysis is converted to |
| A. | acetate |
| B. | lactate |
| C. | monosodium phosphate |
| D. | pyruvic acid |
| Answer» C. monosodium phosphate | |
| 8. |
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 | |
| 9. |
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. | |
| 10. |
What is present in the stomach to prevent self-digestion? |
| A. | Mucus |
| B. | acid |
| C. | Enzymes |
| D. | hormones |
| Answer» B. acid | |
| 11. |
The sugar which forms major component of nucleic acids is |
| A. | ribose |
| B. | galactose |
| C. | mannose |
| D. | maltose |
| Answer» B. galactose | |
| 12. |
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 | |
| 13. |
Which of the following is not a disaccharide? |
| A. | Amylose |
| B. | Cellobiose |
| C. | Lactose |
| D. | None of these |
| Answer» B. Cellobiose | |
| 14. |
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 | |
| 15. |
The main site for gluconeogenesis is |
| A. | kidney |
| B. | liver |
| C. | brain |
| D. | muscle |
| Answer» C. brain | |
| 16. |
A catabolic intermediate which stimulates phosphofructokinase would stimulate |
| A. | gluconeogenesis |
| B. | glycolysis |
| C. | glycogen synthesis |
| D. | none of these |
| Answer» C. glycogen synthesis | |
| 17. |
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 | |
| 18. |
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 | |
| 19. |
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. | |
| 20. |
a-amylose is similar to |
| A. | -sheets |
| B. | -turned coils |
| C. | -helices |
| D. | the hydrophobic core |
| Answer» D. the hydrophobic core | |
| 21. |
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. | |
| 22. |
Hydrolysis of lactose yields |
| A. | galactose and fructose |
| B. | galactose and glucose |
| C. | glucose and fructose |
| D. | fructose and galactose |
| Answer» C. glucose and fructose | |
| 23. |
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 | |
| 24. |
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. | |
| 25. |
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 | |
| 26. |
Which of the following can act as precursors for gluconeogenesis? |
| A. | Lactate |
| B. | Glycerol |
| C. | Alanine |
| D. | All of these |
| Answer» E. | |
| 27. |
A common way that cells capture the energy released during the breakdown of large molecules is to add electrons to smaller, specialized molecules that can accept them. This process of electron acceptance is otherwise known as |
| A. | biosynthesis |
| B. | metabolism |
| C. | reduction |
| D. | catalysis |
| Answer» D. catalysis | |
| 28. |
Humans are unable to digest |
| A. | starch |
| B. | complex carbohydrates |
| C. | denatured proteins |
| D. | cellulose |
| Answer» E. | |
| 29. |
How many ATP equivalents per mole of glucose input are required for gluconeogenesis? |
| A. | 2 |
| B. | 6 |
| C. | 8 |
| D. | 4 |
| Answer» C. 8 | |
| 30. |
Which of the following compounds is responsible for coordinated regulation of glucose and glycogen metabolism? |
| A. | NAD |
| B. | <sup>+</sup> |
| C. | Fructose 2,6 bisphosphate |
| D. | Acetyl-CoA |
| E. | Fructose 1,6 bisphosphate |
| Answer» C. Fructose 2,6 bisphosphate | |
| 31. |
Saliva contains all of the following except |
| A. | hormones |
| B. | amylase |
| C. | bacteria-killing enzymes |
| D. | antibodies |
| Answer» B. amylase | |
| 32. |
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 | |
| 33. |
Storage polysaccharide made by animals is |
| A. | amylopectin |
| B. | glycogen |
| C. | cellulose |
| D. | collagen |
| Answer» C. cellulose | |
| 34. |
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 | |
| 35. |
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 | |
| 36. |
Fructose is metabolized by |
| A. | fructose 1-phosphate pathway |
| B. | fructose 6-phosphate pathway |
| C. | glyceraldehyde 3-phosphate pathway |
| D. | both (a) and (b) |
| Answer» E. | |
| 37. |
Glycolysis reactions take place in |
| A. | cytoplasm |
| B. | cell membrane |
| C. | cell wall |
| D. | plasmids |
| Answer» B. cell membrane | |
| 38. |
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 | |
| 39. |
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 | |
| 40. |
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 | |
| 41. |
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 | |
| 42. |
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 | |
| 43. |
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. | |
| 44. |
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 | |
| 45. |
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 | |
| 46. |
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 | |
| 47. |
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. | |
| 48. |
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. | |
| 49. |
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 | |
| 50. |
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 | |