Question 1

Which of the following best describes the mechanism of action for steroid hormones such as cortisol?

Accepted Answer

They bind to intracellular receptors, which then function as transcription factors to regulate gene expression.

Question 2

A patient with a genetic defect in the insulin receptor substrate (IRS) would most likely have impaired activation of which of the following enzymes after insulin binding?

Accepted Answer

Phosphoinositide 3-kinase (PI3K)

Question 3

Which of the following is TRUE regarding the metabolic state in the liver during fasting?

Accepted Answer

Gluconeogenesis and glycogenolysis are enhanced.

Question 4

Which hormone is primarily responsible for activating glycogenolysis in skeletal muscle during the fasted state?

Accepted Answer

Epinephrine

Question 5

A hydrophobic hormone is most likely to:

Accepted Answer

Diffuse through the plasma membrane and bind to an intracellular receptor.

Question 6

Which of the following best explains why cortisol requires a transport protein in the blood?

Accepted Answer

Cortisol is hydrophobic and poorly soluble in plasma.

Question 7

Which of the following is a direct effect of insulin signaling in skeletal muscle?

Accepted Answer

Increased glucose uptake via GLUT4 transporters

Question 8

During the fasted state, which hormone is elevated and promotes lipolysis in adipose tissue?

Accepted Answer

Glucagon

Question 9

Which of the following best describes the role of G-protein coupled receptors (GPCRs) in hormone signaling?

Accepted Answer

They activate intracellular second messengers such as cAMP.

Question 10

A mutation that prevents the activation of phospholipase C would most directly impair which signaling pathway?

Accepted Answer

The pathway that generates inositol-1,4,5-trisphosphate (IP3) and diacylglycerol (DAG) as second messengers

Question 11

Which of the following is a correct sequence of events for glucagon signaling via a G-protein coupled receptor?

Accepted Answer

Glucagon binds receptor → G-protein activation → adenylyl cyclase activation → cAMP increase

Question 12

Which of the following best explains why the brain relies on glucose as its primary fuel in both the fed and fasted states?

Accepted Answer

The brain cannot metabolize fatty acids due to the blood-brain barrier.

Question 13

Which of the following is a function of cortisol during the fasted state?

Accepted Answer

Enhances gluconeogenesis and protein catabolism

Question 14

A patient is given a drug that blocks GLUT4 translocation to the plasma membrane. Which tissue would be most affected in terms of glucose uptake after a meal?

Accepted Answer

Skeletal muscle

Question 15

Which of the following best describes the role of second messengers in hormone signaling?

Accepted Answer

They are intracellular molecules that amplify the signal from a hormone-receptor interaction.

Question 16

Which of the following is a direct effect of glucagon on the liver during fasting?

Accepted Answer

Increased gluconeogenesis

Question 17

A researcher discovers a new hormone that is hydrophilic and acts rapidly by altering protein phosphorylation. Which type of receptor is this hormone most likely to use?

Accepted Answer

G-protein coupled receptor

Question 18

Which of the following best explains why insulin promotes glycogen synthesis in the liver after a meal?

Accepted Answer

Insulin activates protein phosphatases, which dephosphorylate and activate glycogen synthase.

Question 19

Which of the following is a key difference between endocrine and paracrine signaling?

Accepted Answer

Endocrine signaling involves hormones traveling through the bloodstream, while paracrine signaling acts locally.

Question 20

A patient with a deficiency in phosphoinositide metabolism would most likely have impaired:

Accepted Answer

Release of intracellular calcium in response to hormone signaling

Metabolic Regulation and Hormonal Signaling: Study Guide

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