ANP Exam 2 Practice Questions – Step-by-Step Study Guidance

Q1. Which of the following statements about the resting membrane potential is TRUE?

Background

Topic: Resting Membrane Potential

This question tests your understanding of the factors that establish and maintain the resting membrane potential in cells, especially neurons and muscle cells.

Key Terms and Concepts:

• Resting membrane potential: The voltage difference across the cell membrane when the cell is not actively sending a signal.

• Na+ and K+ gradients: The difference in sodium and potassium ion concentrations inside and outside the cell.

• Extracellular proteins: Proteins found outside the cell, which may or may not contribute to membrane potential.

Step-by-Step Guidance

1. Recall that the resting membrane potential is typically a negative value (e.g., -70 mV in neurons), not zero or positive.

2. Consider what causes this negative potential: mainly the movement of K+ out of the cell and Na+ into the cell, and the selective permeability of the membrane to these ions.

3. Think about whether extracellular proteins or concentration gradients of ions are more important in establishing this potential.

4. Review each answer choice and eliminate those that contradict what you know about the resting membrane potential.

Try solving on your own before revealing the answer!

Q2. When a peptide or catecholamine hormone binds to surface receptors at a target cell, what happens?

Background

Topic: Hormone Signaling Mechanisms

This question tests your knowledge of how peptide and catecholamine hormones signal through cell surface receptors and what intracellular events follow.

Key Terms and Concepts:

• Peptide/catecholamine hormones: Water-soluble hormones that cannot cross the cell membrane and thus bind to receptors on the cell surface.

• Second messenger: An intracellular signaling molecule released in response to receptor activation (e.g., cAMP, IP3).

Step-by-Step Guidance

1. Recall that peptide and catecholamine hormones are not lipid-soluble, so they cannot enter the cell directly.

2. Think about what happens when these hormones bind to their receptors: does the hormone enter the cell, or does it trigger a cascade inside the cell?

3. Review the concept of second messengers and how they relay signals from the cell surface to the inside of the cell.

4. Eliminate answer choices that do not fit the known mechanism of action for these hormones.

Try solving on your own before revealing the answer!

Q3. Which of the following statements about peptide hormones is FALSE?

Background

Topic: Peptide Hormone Properties

This question asks you to identify which statement does NOT accurately describe peptide hormones.

Key Terms and Concepts:

• Peptide hormones: Hormones made of amino acids, usually water-soluble, and often act via cell surface receptors.

• Signal transduction: The process by which a signal on a cell's surface is converted into a specific cellular response.

• Half-life: The time it takes for half of the hormone to be removed from the bloodstream.

• Carrier proteins: Proteins that transport substances in the blood; peptide hormones are usually free in plasma, not bound.

Step-by-Step Guidance

1. Review each statement and recall the general properties of peptide hormones (how they are synthesized, transported, and how they act).

2. Identify which statements are true based on your knowledge of peptide hormone synthesis, signaling, and transport.

3. Look for the statement that contradicts what you know about peptide hormones, especially regarding their presence in the bloodstream and their need for carrier proteins.

Try solving on your own before revealing the answer!

Q4. What are catecholamines? (What kind of molecules are they?)

Background

Topic: Hormone Classification

This question tests your ability to classify catecholamines and understand their chemical nature and function.

Key Terms and Concepts:

• Catecholamines: A class of hormones derived from the amino acid tyrosine, including epinephrine, norepinephrine, and dopamine.

• Amine hormones: Hormones derived from single amino acids (tyrosine or tryptophan).

Step-by-Step Guidance

1. Recall the main examples of catecholamines and their roles in the body (e.g., fight-or-flight response).

2. Think about their chemical structure: are they peptides, steroids, or amines?

3. Consider their solubility and how they interact with receptors (surface or intracellular?).

Try answering before checking the explanation!

Q5. What determines the meaning of a message in a signal transduction event?

Background

Topic: Signal Transduction

This question tests your understanding of how cells interpret signals and what factors influence the cellular response to a signaling molecule.

Key Terms and Concepts:

• Signal transduction: The process by which a cell converts an extracellular signal into a functional response.

• Receptor type: The specific protein that binds the signaling molecule and initiates the response.

• Intracellular pathways: The cascade of events inside the cell following receptor activation.

Step-by-Step Guidance

1. Consider whether the same signaling molecule can have different effects in different cells.

2. Think about the role of the receptor and the downstream signaling pathways in determining the cell's response.

3. Reflect on examples where the same hormone produces different effects in different tissues (e.g., epinephrine in heart vs. intestine).

Try to explain in your own words before checking the answer!