Teacher:Given a scientific passage and an answer, generate a question for the given answer.
Teacher: Now, understand the problem? Solve this instance: Passage: The plasma membrane also contains other molecules, primarily other lipids and proteins. The green molecules in Figure above , for example, are the lipid cholesterol. Molecules of cholesterol help the plasma membrane keep its shape. Many of the proteins in the plasma membrane assist other substances in crossing the membrane. Answer: molecules of cholesterol
Student:
What helps the plasma membrane keep its shape?