Question

question 3 (2.5 points)
all of the following about the cell membranes are true except:
cell membranes property varies depending the on types and proportions of molecules composing it
membrane fluidity decreases with increasing cholesterol content
membranes fluidity depends on the length and saturation of its phospholipids fatty acid tails
cell membranes property remains constant and univariable

Explanation:

• The cell membrane is a dynamic structure. Its properties are influenced by the types and proportions of molecules (such as lipids, proteins, and carbohydrates) that compose it. So, the statement “cell membrane’s property varies depending the on types and proportions of molecules composing it” is true.
• Cholesterol has a dual - effect on membrane fluidity. At high temperatures, it decreases fluidity by restraining the movement of phospholipid fatty acid tails. So, “membrane fluidity decreases with increasing cholesterol content” can be a valid statement depending on the context (e.g., when temperature is relatively high).
• The length and saturation of phospholipids' fatty acid tails affect membrane fluidity. Shorter and unsaturated tails increase fluidity. So, “membrane’s fluidity depends on the length and saturation of its phospholipids’ fatty acid tails” is true.
• The cell membrane is not a static structure with constant and unvarying properties. It can change in response to various factors such as temperature, the presence of different molecules, and the cell's physiological state. So, “cell membrane’s property remains constant and unvariable” is false.

Answer:

cell membrane’s property remains constant and unvariable