You could talk about how plants supply food for animals.
E.g cacti provide food and water for desert animals and rodents.
small rodents provide food for larger animals and snakes.
some animals will clean larger animals in a mutualistic relationship.
Answer:
Phospholipids form the basic structure of a cell membrane, called the lipid bilayer. Scattered in the lipid bilayer are cholesterol molecules, which help to keep the membrane fluid consistent. Membrane proteins are important for transporting substances across the cell membrane