Question 1

Which of the following molecules is most likely to freely diffuse across a biological membrane without facilitation?

Accepted Answer

O\_2

Question 2

Biological membranes are described as ________ permeable, which allows them to control the passage of substances. What is the correct term?

Accepted Answer

Selectively

Question 3

Which property most increases a molecule's ability to freely diffuse across a lipid bilayer?

Accepted Answer

Nonpolarity

Question 4

Given the following molecules: Acetamide, Urea, Butyramide. Rank their ability to diffuse across a biological membrane from least to most permeable.

Accepted Answer

Acetamide \u003c Urea \u003c Butyramide

Question 5

Which of the following statements best describes the role of cholesterol in biological membranes?

Accepted Answer

Cholesterol decreases membrane fluidity at high temperatures.

Question 6

A molecule is large, charged, and hydrophilic. How is it most likely to cross a biological membrane?

Accepted Answer

By facilitated diffusion

Question 7

Which equation best describes the net movement of molecules across a membrane due to diffusion?

Accepted Answer

$$J = -D \frac{dC}{dx}$$

Question 8

Which of the following molecules would be LEAST likely to cross a biological membrane without a transporter?

Accepted Answer

Na\^+

Question 9

Which of the following is NOT a feature of selectively permeable membranes?

Accepted Answer

Allowing all molecules to pass freely

Question 10

A cell is placed in a solution containing a high concentration of NaCl. What will happen to water movement across the membrane?

Accepted Answer

Water will move out of the cell by osmosis

Question 11

Which of the following best explains why large polar molecules require transport proteins to cross the membrane?

Accepted Answer

They are repelled by the hydrophobic core of the membrane

Question 12

Which of the following is a correct statement about passive transport?

Accepted Answer

It moves molecules down their concentration gradient

Question 13

Which of the following molecules would diffuse most rapidly across a biological membrane?

Accepted Answer

Methane (CH\_4)

Question 14

Which of the following is a real-life example of facilitated diffusion?

Accepted Answer

Glucose uptake by muscle cells via GLUT transporters

Question 15

Which of the following best describes the permeability of the lipid bilayer to ions?

Accepted Answer

Impermeable without transport proteins

Question 16

Which of the following is NOT a factor that affects the rate of diffusion across a membrane?

Accepted Answer

ATP concentration

Question 17

Which of the following best describes the movement of water across a membrane?

Accepted Answer

Osmosis

Question 18

Which of the following molecules would require a transporter to cross the membrane?

Accepted Answer

Glucose

Question 19

Which of the following is a correct statement about the structure of biological membranes?

Accepted Answer

They contain both hydrophobic and hydrophilic regions

Question 20

Which of the following best describes the function of protein channels in membranes?

Accepted Answer

They facilitate the movement of specific ions and polar molecules

Biological Membrane Transport: Diffusion and Selective Permeability

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