1.
Which of the following statements is true about catabolic pathways?
Correct Answer
B. They are usually coupled with anabolic pathways to which they supply energy in the form of ATP.
Explanation
Catabolic pathways involve the breakdown of complex molecules into simpler ones. They are usually coupled with anabolic pathways, which involve the synthesis of complex molecules from simpler ones. In this coupling, catabolic pathways supply energy in the form of ATP to anabolic pathways. This allows the energy released during the breakdown of molecules in catabolism to be used for the synthesis of new molecules in anabolism. Therefore, the statement "They are usually coupled with anabolic pathways to which they supply energy in the form of ATP" is true.
2.
The hydrolysis of sucrose by the enzyme sucrase results in
Correct Answer
E. Breaking the bond between glucose and fructose by breaking a water molecule and adding an H+ to one and an OH- to the other.
Explanation
The hydrolysis of sucrose by the enzyme sucrase involves breaking the bond between glucose and fructose. This is achieved by breaking a water molecule and adding an H+ ion to one molecule and an OH- ion to the other. This process is known as hydrolysis, where water is used to break down a compound into its constituent parts. In the case of sucrose, the bond between glucose and fructose is broken, resulting in the formation of two separate molecules.
3.
Which term most precisely describes the general process of combining small molecules to form large molecules ?
Correct Answer
E. Anabolism
Explanation
Anabolism is the term that most precisely describes the general process of combining small molecules to form large molecules. This process involves the synthesis of complex molecules from simpler ones, requiring energy input. It is a key component of metabolism, which refers to all the chemical reactions that occur in an organism to maintain life. Catabolism, on the other hand, refers to the breakdown of complex molecules into simpler ones, while exothermic reaction and dehydration reaction are more specific types of chemical reactions that may or may not involve the formation of large molecules.
4.
After digestion, what happens when glucose is not immediately metabolized or converted to glycogen?
Correct Answer
C. Hyperglycemia will develop.
Explanation
When glucose is not immediately metabolized or converted to glycogen, it can lead to an increase in blood glucose levels, resulting in hyperglycemia. This occurs when there is an excess of glucose in the bloodstream, which can happen if the body is unable to properly regulate blood sugar levels. Hyperglycemia can have various causes, such as insulin resistance or insufficient insulin production. If left untreated, it can lead to complications such as damage to blood vessels, nerves, and organs.
5.
Which of the following statements does not describe glycolysis?
Correct Answer
A. It is an aerobic process.
Explanation
Glycolysis is a metabolic pathway that occurs in the cytoplasm of the cell and breaks down a molecule of glucose into two molecules of pyruvate. It is also known as the Embden-Meyerhoff pathway. One of the key features of glycolysis is that it does not require oxygen, making it an anaerobic process. Therefore, the statement "It is an aerobic process" does not describe glycolysis accurately.
6.
How many molecules of ATP are produced from the metabolism of 1 molecule of glucose?
Correct Answer
B. 36
Explanation
During cellular respiration, one molecule of glucose produces a total of 36 molecules of ATP. This occurs through a series of reactions, including glycolysis, the Krebs cycle, and oxidative phosphorylation. In glycolysis, two molecules of ATP are produced. The Krebs cycle generates two more ATP molecules. Finally, oxidative phosphorylation, which occurs in the electron transport chain, produces a total of 32 ATP molecules. Therefore, the correct answer is 36.
7.
The following are the important products of glycolysis except
Correct Answer
B. 2 molecules of ADP.
Explanation
Glycolysis is the metabolic pathway that converts glucose into pyruvate, producing ATP and NADH in the process. The important products of glycolysis include 2 molecules of NADH, which are produced when NAD+ is reduced to NADH during the conversion of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate. Additionally, glycolysis produces 2 molecules of pyruvate, which are the end products of the pathway, and 2 molecules of ATP, which are generated through substrate-level phosphorylation. However, ADP is not a product of glycolysis; it is a reactant that is converted to ATP during the process. Therefore, the correct answer is 2 molecules of ADP.
8.
The following conditions / processes will remove excess glucose from the blood except
Correct Answer
B. Glycogenolysis.
Explanation
Glycogenolysis is the process of breaking down glycogen into glucose to release it into the bloodstream. This process actually increases the amount of glucose in the blood rather than removing excess glucose. On the other hand, glycogenesis is the process of converting glucose into glycogen for storage, which helps remove excess glucose from the blood. The presence of insulin also helps remove excess glucose by facilitating its uptake into cells. Conversion to fat is another way of removing excess glucose from the blood by storing it as energy reserves. Therefore, the only process that does not remove excess glucose from the blood is glycogenolysis.
9.
Which of the following functions is not performed by insulin?
Correct Answer
A. It promotes glucose absorption in the bloodstream.
Explanation
Insulin is a hormone produced by the pancreas that plays a crucial role in regulating blood sugar levels. It promotes the cellular uptake of glucose, meaning it helps cells take in glucose from the bloodstream. It also inhibits glycogenolysis, which is the breakdown of glycogen into glucose. Additionally, insulin promotes the oxidation of glucose in the cell, which is the process of converting glucose into energy. However, insulin does not directly promote glucose absorption in the bloodstream. Instead, it facilitates the movement of glucose from the bloodstream into the cells.
10.
All of the following conditions may likely happen when carbohydrate is totally removed from the diet except
Correct Answer
D. Glucose may accumulate in the bloodstream resulting to hyperglycemia.
Explanation
When carbohydrate is totally removed from the diet, the body will switch into preparing glucose from non-carbohydrate sources. This is because glucose is the primary source of energy for the body and it needs to be maintained at a certain level for proper functioning. The blood may become acidic due to the formation of ketones and acids as byproducts of the metabolism of fatty acids. This is known as ketosis. The person may lose weight because the body will start using stored fat for energy. However, glucose will not accumulate in the bloodstream resulting in hyperglycemia since there is no source of glucose in the diet.