Trypsin functions best in which of the following conditions?

Correct Answer: A

Rationale: The correct answer is A: basic. Trypsin is a protease enzyme that functions best in basic conditions, specifically at a pH around 8. This is because its active site contains amino acid residues that are positively charged at basic pH, facilitating substrate binding and catalysis. In acidic conditions (choice B), the active site residues may become protonated and lose their positive charge, leading to decreased enzyme activity. Neutral conditions (choice C) are suboptimal for trypsin as it requires basic pH for optimal function. Low pH (choice D) is also not ideal for trypsin as it can denature the enzyme and hinder its catalytic activity.

Correct Answer: D

Rationale: The correct answer is D: carbohydrates. Maltose is a disaccharide composed of two glucose molecules, which are carbohydrates. During digestion, carbohydrates such as starch are broken down into maltose by enzymes like amylase. Lipids (A), proteins (B), and nucleic acids (C) do not directly contribute to the formation of maltose in the digestive process. Therefore, the source of maltose during digestion is carbohydrates, making option D the correct choice.

Correct Answer: C

Rationale: The correct answer is C: fat droplets. When the liver is unable to break down red blood cells, it affects the metabolism of hemoglobin, leading to decreased production of bile salts necessary for emulsifying fats. This results in decreased production of fat droplets. A: Maltose is a disaccharide formed from the breakdown of starch, not directly related to red blood cell breakdown. B: Peptides are formed from protein digestion, not directly affected by the breakdown of red blood cells. D: Nucleotides are building blocks of nucleic acids and not directly related to red blood cell breakdown.

Correct Answer: C

Rationale: The correct answer is C because salivary glands secrete an enzyme called amylase that catalyzes the breakdown of carbohydrates into maltose. Amylase specifically targets the bonds between glucose molecules in carbohydrates, resulting in the production of maltose. Therefore, the reaction of carbohydrates + H2O -> maltose is catalyzed by salivary gland secretions. Choice A is incorrect because the breakdown of proteins into peptides is not catalyzed by salivary gland secretions. Choice B is incorrect as peptides are broken down into amino acids, not the other way around. Choice D is incorrect as the breakdown of fats into fatty acids and glycerol is not catalyzed by salivary gland secretions.

Correct Answer: A

Rationale: The correct answer is A because during protein digestion, specific enzymes such as proteases break down proteins into amino acids. Proteins are large molecules made up of amino acids, and the body needs to break them down into individual amino acids for absorption and utilization. Choices B, C, and D are incorrect because hormones do not directly break down proteins, and proteins are not broken down into simple sugars or complex starches during digestion. It is essential to understand the role of enzymes in protein digestion to select the correct answer.