Exam 2 Biology

Question 1

Which of the following statements about diffusion is true?

Answer 1

It is a passive process.

Question 2

Which of the following structural arrangements of the components in biological membranes facilitates the cell membrane’s property of selective permeability?

Answer 2

Proteins sandwiched between two layers of phospholipids.

Question 3

What function do carbohydrates fulfill in the plasma membrane?

Answer 3

Cell-to-cell recognition

Question 4

Which of the following substances would be most likely to pass through the plasma membrane without the help of a transport protein?

Answer 4

A nonpolar molecule, such as a hydrocarbon

Question 5

Which of the following molecules is most likely to passively diffuse across the plasma membrane?

Answer 5

Carbon dioxide

Question 6

Which of the following statements concerning carbohydrates associated with the plasma membrane is correct?

Answer 6

Membrane carbohydrates function primarily in cell-cell recognition.

Question 7

Which of these statements describes some aspect of facilitated diffusion?

Answer 7

Facilitated diffusion of solutes may occur through channel or transport proteins in the membrane.

Question 8

Which of the following molecules are most abundant in the plasma membrane?

Answer 8

Phospholipids

Question 9

How does the “fluid mosaic model” describe the structure of the plasma membrane?

Answer 9

Proteins in the membrane contribute to the mosaic quality of the membrane while the lateral and rotational movements of phospholipids contribute to its fluidity.

Question 10

Why is energy required for active transport?

Answer 10

Because it moves solutes against their concentration gradient