Question

the cell membrane-practice problems
48.00 points possible | due friday 10/24/25 at 11:59 pm
0/2 points earned
many people enjoy boating and fishing on lake superior in the northern united states. at the surface, the water temperature can be as high as 70°f, perfect for taking a swim in the shallow bays. but the lake is over 1000 feet deep in some areas and, in these depths, the water stays around 45°f even in the middle of summer.
there are fish living throughout the lake. rainbow trout living near the surface and deepwater sculpin living in the deeps both need to maintain similar levels of fluidity and permeability in their cell membranes, despite the great difference in the temperature of the environments in which these fish live.
how can the deepwater sculpin prevent their membranes from becoming rigid and impermeable in the cold depths of lake superior? select all that apply.
the composition of lipids in cell membranes cant be changed so the fish must have another way to adapt to the cold conditions.
deepwater sculpin have phospholipids with shorter tails and thus weaker hydrophobic interactions between neighboring lipids in their membranes.
deepwater sculpin need to have more unsaturated phospholipids in their cell membranes.
deepwater sculpin have a larger number of phospholipids in each cell membrane.

Explanation:

• Phospholipids with shorter tails have weaker hydrophobic interactions, which helps maintain membrane fluidity in cold temperatures. Unsaturated phospholipids have kinks in their tails that prevent tight packing, also contributing to membrane fluidity.
• The composition of lipids in cell membranes can be changed (so the first option is incorrect). The number of phospholipids in each cell membrane (the fourth option) does not directly relate to preventing membrane rigidity in cold.

Answer:

Deepwater sculpin have phospholipids with shorter tails and thus weaker hydrophobic interactions between neighboring lipids in their membranes. Deepwater sculpin need to have more unsaturated phospholipids in their cell membranes.