The liberation of proteins to free amino acids (final digestive step) occur in all of the following EXCEPT:

Correct Answer: D

Rationale: The correct answer is D: stomach. Proteins are broken down into amino acids through the process of digestion. In the stomach, proteins are broken down into smaller peptides, not free amino acids. The final step of liberating proteins into free amino acids occurs in the enterocyte cytoplasm, where absorbed nutrients are further processed. The brush border of the small intestine is where the final stages of digestion take place before absorption. The small intestine lumen is the space where digestion occurs, but the actual liberation of proteins into free amino acids happens in the enterocyte cytoplasm.

Correct Answer: B

Rationale: Step 1: Albumin binds more thyroid hormones than TBG due to its higher concentration in the blood. Step 2: TBG has higher affinity for thyroid hormones than albumin, leading to less free hormone. Step 3: Hence, choice B is correct as albumin has more capacity to bind thyroid hormones. Summary: Choice A is incorrect as significant T3 is produced peripherally. Choice C is incorrect as TBG has higher affinity. Choice D is incorrect as thyroid hormones stimulate lipolysis, not lipogenesis.

Correct Answer: A

Rationale: The correct answer is A: follicle-stimulating hormone (FSH). FSH is the other hormone made by the pituitary gland that helps regulate reproductive cells, along with luteinizing hormone (LH). FSH is responsible for stimulating the growth and maturation of ovarian follicles in females and spermatogenesis in males. Explanation: 1. FSH is directly involved in the reproductive process by stimulating follicle development and sperm production. 2. Epinephrine and norepinephrine are not hormones produced by the pituitary gland and are involved in the stress response. 3. Androgens are male sex hormones produced primarily by the testes, not the pituitary gland. In summary, FSH is the correct answer as it plays a crucial role in regulating reproductive cells, while the other choices are not involved in the reproductive system or are not produced by the pituitary gland.

Correct Answer: B

Rationale: The correct answer is B: melatonin. Melatonin is the hormone involved in regulating rhythmic activities like day/night and seasonal changes through its influence on the body's circadian rhythm. Calcitonin is a hormone that regulates calcium levels in the blood; estrogen is a female sex hormone; and cyclin is a protein involved in cell cycle regulation. Melatonin's role in regulating sleep-wake cycles and responding to changes in light exposure makes it the most appropriate choice for a hormone involved in rhythmic activities.

Correct Answer: B

Rationale: Salivary amylase breaks down starches into simple sugars like maltose. Starch is a complex carbohydrate found in foods like bread, pasta, and rice. When you chew food, salivary amylase in saliva starts the digestion process by breaking down starch molecules. Proteins are broken down by stomach enzymes, roughage (fiber) is not digested by enzymes in the mouth, and fats are primarily digested in the small intestine by pancreatic lipase. Therefore, choice B, starches, is the correct answer as salivary amylase specifically targets this food type for initial breakdown.