Compared to pork/beef insulins, the human insulins:

Correct Answer: B

Rationale: The correct answer is B: Human insulins have a faster kinetics of absorption and elimination compared to pork/beef insulins. This is because human insulins are structurally identical to the insulin produced by the human body, leading to better compatibility and quicker absorption. Pork/beef insulins may have different amino acid sequences, causing slower absorption. Choice A is incorrect as potency is not the distinguishing factor between human and pork/beef insulins. Choice C is incorrect because human insulins typically have shorter biological action half-lives due to faster absorption. Choice D is irrelevant as it does not relate to the comparison between human and pork/beef insulins.

Correct Answer: B

Rationale: Metformin acts by suppressing gluconeogenesis and glucose output from the liver. It inhibits the enzyme responsible for gluconeogenesis, reducing glucose production. This leads to decreased blood glucose levels. Other choices are incorrect because metformin does not directly affect insulin release, insulin receptor upregulation, or insulin degradation.

Correct Answer: B

Rationale: The correct answer is B: Rosiglitazone. Rosiglitazone is a thiazolidinedione that works by activating peroxisome proliferator-activated receptor gamma (PPAR-gamma), which then increases the expression of glucose transporters on the cell membrane. This leads to improved cellular glucose uptake and utilization, thus reversing insulin resistance. Rationale: A. Glibenclamide is a sulfonylurea that stimulates insulin secretion from the pancreas but does not directly affect cellular glucose transporters. C. Acarbose is an alpha-glucosidase inhibitor that delays carbohydrate digestion but does not increase cellular glucose transporters. D. Prednisolone is a corticosteroid that can worsen insulin resistance by increasing blood glucose levels through various mechanisms.

Correct Answer: B

Rationale: The correct answer is B: Lipoxygenase. Corticosteroids inhibit the enzyme lipoxygenase, which is responsible for the production of leukotrienes, potent mediators of inflammation. By inhibiting lipoxygenase, corticosteroids reduce inflammation. Explanation for why the other choices are incorrect: A: Cyclooxygenase - Corticosteroids do not directly inhibit cyclooxygenase, which is the enzyme targeted by NSAIDs like aspirin and ibuprofen. C: Phospholipase - Corticosteroids primarily inhibit phospholipase A2, not phospholipase, to reduce the production of arachidonic acid. D: A - This choice is unclear and does not specify a particular enzyme. Therefore, it is not a valid answer.

Correct Answer: D

Rationale: Step 1: Dexamethasone is a long-acting glucocorticoid, providing sustained anti-inflammatory effects. Step 2: It is more potent than prednisolone, requiring lower doses for similar effects. Step 3: Dexamethasone is more selective, with higher affinity for glucocorticoid receptors. Step 4: Therefore, the correct answer is D, as it accurately describes the differences between dexamethasone and prednisolone. Summary: Choices A, B, and C are incorrect because dexamethasone possesses all these characteristics, making it a more effective glucocorticoid compared to prednisolone.