Which of the following processes describes the conversion of glucose to pyruvic acid during glycolysis?

Correct Answer: B

Rationale: The correct answer is B: Glycolysis. Glycolysis is the metabolic pathway where glucose is broken down to produce pyruvic acid and ATP, generating energy in the form of ATP. Glycogenesis (choice A) is the process of glycogen synthesis, Glycogenolysis (choice C) is the breakdown of glycogen to release glucose, and Gluconeogenesis (choice D) is the synthesis of glucose from non-carbohydrate sources. Therefore, during glycolysis, glucose is converted into pyruvic acid, which is a crucial step in energy production.

Correct Answer: D

Rationale: The correct answer is D: Pyruvic acid. The end product of glycolysis is pyruvic acid, not lactic acid, ATP, or NADPH. Pyruvic acid is a key intermediary in cellular respiration and can be further metabolized to produce energy through processes like the citric acid cycle and oxidative phosphorylation. Lactic acid is produced in the absence of oxygen during fermentation, ATP is a product of cellular respiration but not the direct end product of glycolysis, and NADPH is generated in other metabolic pathways such as the pentose phosphate pathway, not in glycolysis.

Correct Answer: A

Rationale: The correct answer is A. Macrophages are not found abundantly in the blood; they are present in tissues and organs. Macrophages are tissue-resident immune cells that play a key role in immune responses and are derived from monocytes produced in the bone marrow. Choice B is correct as macrophages are larger than neutrophils. Choice C is correct as macrophages are long-lived cells. Choice D is correct as macrophages originate in the bone marrow as monocytes and differentiate into macrophages once they migrate to various tissues and organs.

Correct Answer: B

Rationale: The correct answer is B: Serotonin. Serotonin is a neurotransmitter known for its role in mood regulation, promoting feelings of happiness and well-being. It helps regulate emotions, sleep, and appetite. Low levels of serotonin have been linked to conditions like depression and anxiety. Choice A, Dopamine, is more associated with pleasure and reward pathways in the brain. GABA (Choice C) is an inhibitory neurotransmitter involved in reducing neuronal excitability, not primarily linked to happiness. Acetylcholine (Choice D) is involved in muscle contraction and has functions related to memory and attention, but it is not primarily associated with feelings of happiness and well-being.