How do protein kinases affect enzymes?
- A. They add a phosphate group (phosphorylation) to the enzyme.
- B. They increase the release of an enzyme.
- C. They break down the enzyme.
- D. They increase the secretion of an enzyme.
Correct Answer: A
Rationale: Correct Answer: A
Rationale:
1. Protein kinases add a phosphate group to enzymes through phosphorylation.
2. Phosphorylation alters enzyme activity and can activate or deactivate enzymes.
3. This process regulates enzyme function and signaling pathways.
Summary of other choices:
B. Incorrect - Protein kinases do not increase enzyme release; they modify enzyme activity.
C. Incorrect - Protein kinases do not break down enzymes; they regulate their activity.
D. Incorrect - Protein kinases do not increase enzyme secretion; they modify enzyme function through phosphorylation.
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Jane Doe, 23, received her NPH insulin injection at 7:30 A.M., but due to oversight and a long wait in the x-ray department, she has not eaten for 14 hours. The nurse can anticipate which complication?
- A. Dehydration
- B. Ketoacidotic coma
- C. Insulin reaction
- D. Hyperosmolar hyperglycemic coma
Correct Answer: C
Rationale: Not eating after insulin injection can cause hypoglycemia, or an insulin reaction, due to the lack of food to balance the insulin effect.
What findings are commonly found in a patient with a prolactinoma?
- A. Gynecomastia in men
- B. Profuse menstruation in women
- C. Excess follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
- D. Signs of increased intracranial pressure, including headache, nausea, and vomiting
Correct Answer: A
Rationale: Prolactinomas often cause gynecomastia in men and other symptoms due to increased prolactin secretion.
Injecting cocaine may cause a hypertensive crisis or stroke, and if the cocaine is inhaled frequently, it may destroy the tissues in the nose. Which of the following best describes how cocaine causes these adverse effects?
- A. Blocks alpha adrenergic receptors
- B. Blocks muscarinic receptors for ACh
- C. Blocks reuptake of noradrenaline released from adrenergic nerves
- D. Depletes norepinephrine from adrenergic nerve endings
Correct Answer: C
Rationale: Cocaine blocks the reuptake of noradrenaline from adrenergic nerves, leading to excessive stimulation of adrenergic receptors. This causes increased blood pressure, which can result in a hypertensive crisis or stroke. Additionally, the vasoconstrictive effects of excess noradrenaline can lead to tissue damage in the nose when cocaine is inhaled frequently. Choices A and B are incorrect because cocaine does not directly block alpha adrenergic or muscarinic receptors. Choice D is incorrect because cocaine does not deplete norepinephrine from adrenergic nerve endings but rather increases its concentration by blocking reuptake.
Which of the following is NOT true of glucagon?
- A. produced by the pancreas
- B. increases blood glucose levels
- C. promotes the use of fat and protein instead of glucose
- D. stimulates the liver to store glucose as glycogen
Correct Answer: D
Rationale: The correct answer is D because glucagon actually stimulates the liver to release glucose into the bloodstream, not store glucose as glycogen. Glucagon helps increase blood glucose levels by promoting the breakdown of glycogen into glucose, and it also promotes the use of fat and protein for energy when glucose levels are low. Choices A, B, and C are all true statements about glucagon, making them incorrect options in this context.
Tropic hormones ________.
- A. include ACTH and TSH
- B. do not regulate the function of other endocrine glands
- C. exert their effects on cells by direct gene activation
- D. include GH and PRL
Correct Answer: A
Rationale: The correct answer is A because tropic hormones are hormones that regulate the function of other endocrine glands, such as ACTH (adrenocorticotropic hormone) and TSH (thyroid-stimulating hormone). These hormones stimulate the target glands to release their own hormones. Choice B is incorrect because tropic hormones specifically regulate other endocrine glands. Choice C is incorrect because tropic hormones typically exert their effects by binding to specific receptors on target cells, rather than directly activating genes. Choice D is incorrect because GH (growth hormone) and PRL (prolactin) are not tropic hormones as they do not directly regulate the function of other endocrine glands.