Final answer:
Membrane fluidity is important for maintaining homeostasis in cells. Cells control membrane fluidity through adjusting the composition of phospholipids, the presence of cholesterol, and the synthesis and insertion of different types of lipids.
Step-by-step explanation:
Membrane fluidity is important for maintaining homeostasis in cells. It allows for the proper functioning of transport proteins and the selective permeability of the cell membrane. The number of unsaturated fatty acids in the phospholipids of the membrane can affect its fluidity. Unsaturated fatty acids with C-C double bonds introduce kinks in the lipid structure, preventing compact packing and increasing membrane fluidity, while saturated fatty acids with no C-C double bonds decrease fluidity. Temperature also plays a role, as higher temperatures increase fluidity and lower temperatures decrease fluidity.
Cells control membrane fluidity through various mechanisms. One way is by adjusting the composition of the phospholipids. By incorporating more unsaturated fatty acids, cells can increase fluidity. Another mechanism is the presence of cholesterol in animal cell membranes. Cholesterol acts as a buffer, reducing membrane fluidity at high temperatures and increasing it at low temperatures, helping to maintain optimal fluidity for proper cell function. Cells can also regulate fluidity through the synthesis and insertion of different types of lipids into the membrane.