Do You Know Gluconeogenesis?
For something a bit more technical on paper. Have you come across the name Gluconeogenesis? What do you think it entails? It isn't so much of a complicated topic since we have broken it down into simple questions (Swear it). So, here is a short biochemistry quiz on Gluconeogenesis, wherein you can figure out how much you know.
Questions and Answers
- 1.
Which of the following occurs in an individual at rest who has fasted for 12 hours? ​​​​​ ​​​​​​
- A.
Gluconeogenesis process by which glucose is maintained occurs
- B.
Liver Glycogen stores are depleted
- C.
Glycogen synthase is activated in liver
- D.
Phosphorus, pyruvate kinase and glycogen synthase are phosphorylated in liver
Correct Answer
D. Phosphorus, pyruvate kinase and glycogen synthase are phosphorylated in liverExplanation
During a 12-hour fast, the body needs to maintain glucose levels to provide energy. Gluconeogenesis is the process by which glucose is produced from non-carbohydrate sources, such as amino acids and fatty acids. This process occurs in the liver. Phosphorylation is a chemical process in which a phosphate group is added to a molecule, and it plays a crucial role in regulating enzyme activity. In the liver, during fasting, phosphorus, pyruvate kinase, and glycogen synthase are phosphorylated. This phosphorylation helps to inhibit glycogen synthesis and promote gluconeogenesis, ensuring a steady supply of glucose for energy production.Rate this question:
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- 2.
What takes place during the conversion of pyruvate to glucose during glyconeogenesis?
- A.
Biotin is required
- B.
CO2 added in one reaction, appears in final product
- C.
Energy is used up in form of GTP
- D.
PDH is the allosteric enzyme used
Correct Answer
A. Biotin is requiredExplanation
During the conversion of pyruvate to glucose during glyconeogenesis, biotin is required. Biotin is a coenzyme that plays a crucial role in the carboxylation reactions involved in the conversion process. It acts as a carrier of activated carbon dioxide (CO2) and transfers it to pyruvate, resulting in the formation of oxaloacetate. This oxaloacetate is then converted into glucose through a series of enzymatic reactions. Therefore, biotin is necessary for the successful conversion of pyruvate to glucose during glyconeogenesis.Rate this question:
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- 3.
What can a high ratio of insulin to glucagon do?
- A.
Promote gluconeogenesis
- B.
Promote glycogenolysis
- C.
Promote synthesis of Glycogen
- D.
Occurs during fasting state
Correct Answer
C. Promote synthesis of GlycogenExplanation
A high ratio of insulin to glucagon can promote the synthesis of glycogen. Insulin stimulates the uptake of glucose by cells and promotes the conversion of glucose into glycogen, which is stored in the liver and muscles for later use. Glucagon, on the other hand, promotes the breakdown of glycogen into glucose, increasing blood sugar levels. Therefore, when there is a high ratio of insulin to glucagon, it indicates a state where insulin is dominant, leading to an increase in glycogen synthesis. This is commonly observed during the fed state when blood glucose levels are high.Rate this question:
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- 4.
Which of the following substrate cannot contribute to net gluconeogenesis in mammalian liver?
- A.
Palmitate
- B.
Glutamate
- C.
Pyruvate
- D.
Alanine
Correct Answer
A. PalmitateExplanation
Palmitate cannot contribute to net gluconeogenesis in mammalian liver because it is a fatty acid, and fatty acids cannot be converted into glucose through gluconeogenesis. Gluconeogenesis is the process of synthesizing glucose from non-carbohydrate sources, such as amino acids and glycerol, but fatty acids cannot be converted into glucose. Therefore, palmitate cannot be used as a substrate for gluconeogenesis in the mammalian liver.Rate this question:
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- 5.
What is the enzyme used in both glycolysis and gluconeogenesis?
- A.
3-phosphoglycerate kinase
- B.
Glucose 6-phosphatase
- C.
Hexokinase
- D.
Pyruvate Kinase
Correct Answer
A. 3-phosphoglycerate kinaseExplanation
3-phosphoglycerate kinase is the correct answer because it is an enzyme that is involved in both glycolysis and gluconeogenesis. In glycolysis, 3-phosphoglycerate kinase catalyzes the conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate, generating ATP. In gluconeogenesis, it catalyzes the reverse reaction, converting 3-phosphoglycerate to 1,3-bisphosphoglycerate. This enzyme plays a crucial role in both pathways, facilitating the interconversion of metabolites and the production of ATP.Rate this question:
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- 6.
What is Gluconeogenesis useful for?
- A.
Regulation body water level
- B.
Regulating blood circulation
- C.
Regulating Blood glucose level
- D.
Maintaining respiration rate
Correct Answer
C. Regulating Blood glucose levelExplanation
Gluconeogenesis is the process by which the body produces glucose from non-carbohydrate sources, such as amino acids and glycerol. This process is important for maintaining blood glucose levels within a normal range, especially during periods of fasting or low carbohydrate intake. By producing glucose, gluconeogenesis helps to ensure that there is a constant supply of fuel for the brain and other organs that rely on glucose as their primary energy source. Therefore, it is useful for regulating blood glucose levels in the body.Rate this question:
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- 7.
What generates glucose in gluconeogenesis?
- A.
Sucrose
- B.
Yeast
- C.
Non carbohydrate carbon substrates
- D.
Carbohydrate carbon substrate
Correct Answer
C. Non carbohydrate carbon substratesExplanation
Gluconeogenesis is a metabolic pathway that involves the synthesis of glucose from non-carbohydrate carbon substrates, such as amino acids, lactate, and glycerol. These substrates can be converted into glucose through a series of enzymatic reactions in the liver and kidneys. Sucrose, yeast, and carbohydrate carbon substrates do not directly generate glucose in gluconeogenesis.Rate this question:
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- 8.
What are main gluconeogenic precursors (in humans)?
- A.
Lactate
- B.
Alanine
- C.
Glycerol
- D.
All of the above
Correct Answer
D. All of the aboveExplanation
The main gluconeogenic precursors in humans are lactate, alanine, and glycerol. Gluconeogenesis is the process by which glucose is synthesized from non-carbohydrate sources. Lactate is produced during anaerobic metabolism, alanine is derived from the breakdown of amino acids, and glycerol is obtained from the breakdown of triglycerides. All three of these precursors can be converted into glucose through various enzymatic reactions, making them important contributors to maintaining blood glucose levels.Rate this question:
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- 9.
Which of the following is Gluconeogenesis often associated with?
- A.
Hexoses
- B.
Tetrose
- C.
Pentose
- D.
Ketosis
Correct Answer
D. KetosisExplanation
Gluconeogenesis is a metabolic pathway that involves the synthesis of glucose from non-carbohydrate sources such as amino acids, lactate, and glycerol. It is often associated with ketosis, a metabolic state in which the body produces ketones as a result of using fat for fuel instead of glucose. During ketosis, the body's glucose levels are low, and gluconeogenesis helps to maintain blood sugar levels by producing glucose from non-carbohydrate sources. Therefore, gluconeogenesis is often associated with ketosis.Rate this question:
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- 10.
Where does gluconeogenesis take place in vertebrates?
- A.
Liver
- B.
Heart
- C.
Stomach
- D.
Intestine
Correct Answer
A. LiverExplanation
Gluconeogenesis is the process of synthesizing glucose from non-carbohydrate sources. It occurs mainly in the liver, which has the necessary enzymes and metabolic pathways to carry out this process efficiently. The liver plays a central role in maintaining blood glucose levels by producing glucose when the body needs it, such as during fasting or low carbohydrate intake. The heart, stomach, and intestine do not have the same capacity for gluconeogenesis as the liver, making the liver the primary site for this metabolic pathway in vertebrates.Rate this question:
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