Question 1

Which of the following best describes the difference between a body surface that is internal versus external?

Accepted Answer

An internal surface is lined by epithelial cells and faces the lumen of organs, while an external surface is exposed directly to the outside world.

Question 2

Which membrane component is primarily responsible for the selective permeability of the cell membrane?

Accepted Answer

Phospholipid bilayer

Question 3

A patient is experiencing dehydration. Which feedback mechanism is most likely to be activated to restore homeostasis?

Accepted Answer

Negative feedback loop involving increased antidiuretic hormone (ADH) release

Question 4

Which of the following best defines the term 'steady state' in physiology?

Accepted Answer

A dynamic equilibrium where input and output are balanced, but energy is continuously used to maintain the state

Question 5

If a cell membrane is composed of a higher proportion of unsaturated fatty acids, how does this affect membrane fluidity?

Accepted Answer

Membrane fluidity increases because unsaturated fatty acids prevent tight packing.

Question 6

Which equation correctly represents the relationship between pH and hydrogen ion concentration $$[H^+]$$?

Accepted Answer

$$pH = -\log_{10} [H^+]$$

Question 7

A person consumes a meal high in salt. Which physiological response helps maintain fluid and electrolyte balance?

Accepted Answer

Increased secretion of aldosterone to promote sodium reabsorption

Question 8

Which of the following best describes the difference between facilitated diffusion and active transport?

Accepted Answer

Facilitated diffusion moves substances down their concentration gradient without energy input, while active transport moves substances against their gradient using ATP.

Question 9

Which of the following is a correct statement about the chemical bonds formed between amino acids in a protein?

Accepted Answer

Amino acids are joined by peptide bonds to form the primary structure.

Question 10

Which of the following best explains how enzymes increase the rate of chemical reactions?

Accepted Answer

Enzymes lower the activation energy, allowing reactions to proceed faster.

Question 11

A patient with metabolic acidosis has a blood pH of 7.20. Which buffer system is most important in compensating for this change?

Accepted Answer

Bicarbonate buffer system

Question 12

Which of the following is the correct chemical formula for a carbohydrate, and what does it indicate about the ratio of carbon, hydrogen, and oxygen?

Accepted Answer

$$C_nH_{2n}O_n$$, indicating a 1:2:1 ratio of C:H:O

Question 13

Which of the following best describes the role of hemoglobin in oxygen transport?

Accepted Answer

Hemoglobin binds oxygen in the lungs and releases it in tissues where the partial pressure of oxygen is low.

Question 14

Which of the following factors can decrease the affinity of hemoglobin for oxygen, facilitating oxygen release in tissues?

Accepted Answer

Increased pCO$$_2$$, decreased pH, and increased temperature

Question 15

Which of the following is a correct statement about the difference between acids and bases in the body?

Accepted Answer

Acids donate protons ($$H^+$$), while bases accept protons.

Question 16

A mutation causes a change in the primary structure of a protein. Which level of protein structure is directly affected?

Accepted Answer

Primary structure

Question 17

Which of the following best describes the function of membrane channels?

Accepted Answer

They allow passive movement of water-soluble molecules across the membrane.

Question 18

Which of the following is a correct statement about the energy of electrons in atoms?

Accepted Answer

Electrons farther from the nucleus have higher energy than those closer to the nucleus.

Question 19

Which of the following is a correct example of a negative feedback loop in human physiology?

Accepted Answer

Regulation of blood glucose by insulin

Question 20

Which of the following best describes the difference between saturated and unsaturated fatty acids?

Accepted Answer

Saturated fatty acids have no double bonds, while unsaturated fatty acids have one or more double bonds.

Anatomy & Physiology Study Guide: Membrane Dynamics, Fluid Balance, Metabolism, and Molecular Interactions

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