Question

The transition temperature of a lipid bilayer depends on the particular lipids of which it is made. Which of the following factors is NOT a major factor determining the transition temperature of the lipid bilayer?

1) Size of the lipid molecules
2) Presence of double bonds in the lipid tails
3) Presence of cholesterol in the lipid bilayer
4) Concentration of ions in the surrounding solution

Answer 1

The concentration of ions in the surrounding solution is not a major factor determining the transition temperature of the lipid bilayer. Factors such as lipid size, double bonds in the tails, and cholesterol presence are crucial in influencing membrane fluidity and transition temperature.

Step-by-step explanation:

The factor that is NOT a major factor determining the transition temperature of the lipid bilayer is the concentration of ions in the surrounding solution.

In regards to membrane fluidity and transition temperature:

• The size of the lipid molecules is important because larger molecules can affect how tightly packed the lipids are in the bilayer.
• The presence of double bonds in the lipid tails creates bends (kinks) that prevent the lipids from packing tightly, increasing fluidity and affecting transition temperature.
• The presence of cholesterol in the lipid bilayer can act as a buffer to temperature changes, stabilizing the membrane's fluidity.

However, the concentration of ions in the surrounding solution does not have a direct effect on the lipid bilayer's transition temperature but can affect transport across the membrane.