Question

Which of the following statements is true regarding the structure and function of the cell membrane?

a. A monolayer of phospholipids comprises the majority of the membrane structure.
b. The phospholipids are used to provide passage of a select group of polar and nonpolar molecules.
c. All proteins found within the membrane allow for passage of molecules through the membrane.
d. Carbohydrates are only found on the interior of the cell and therefore are not a part of the membrane.
e. Proteins embedded in the phospholipids can be used to facilitate transport of molecules both against and with their gradient.

Answer 1

The cell membrane is composed of a phospholipid bilayer with embedded proteins. Carbohydrates are found on the exterior of the cell and are an integral part of the membrane. Proteins embedded in the phospholipids can facilitate the transport of molecules both against and with their gradient.

Step-by-step explanation:

The cell membrane is composed of a phospholipid bilayer, with proteins embedded within. The phospholipids form the majority of the membrane structure, not a monolayer as mentioned in option a. The proteins in the membrane serve various functions, including facilitating the passage of molecules. However, not all proteins allow for the passage of molecules, as stated in option c. Carbohydrates are actually found on the exterior of the cell and are an integral part of the membrane, aiding in cell recognition. Therefore, option d is incorrect. Lastly, proteins embedded in the phospholipids can indeed facilitate the transport of molecules both against and with their gradient, as mentioned in option e.