What are the three main components of the cell membrane?

Phospholipids, cholesterol, and proteins.

Fill in the blank: The hydrophilic head of a phospholipid is made of a ___ molecule.

Phosphate

True or False: Cholesterol decreases the fluidity of the cell membrane.

False. Cholesterol helps to maintain the fluidity of the cell membrane.

What role do integral proteins play in the cell membrane?

Integral proteins are embedded in the phospholipid bilayer and transport larger molecules across the membrane.

Riddle: I am a barrier that lets some things in and keeps others out. What am I?

The cell membrane.

Fill in the blank: The model that describes the structure and function of the cell membrane is known as the ___ model.

Fluid mosaic

What influences the fluidity of the cell membrane?

Temperature, cholesterol, and the types of fatty acids present in phospholipids.

Short Answer: What types of molecules can easily pass through the cell membrane?

Small, nonpolar molecules such as oxygen and carbon dioxide.

Multiple Choice: Which of the following molecules requires transport proteins to cross the cell membrane? A) Oxygen B) Water C) Glucose D) Carbon Dioxide

C) Glucose

True or False: Ions can freely cross the phospholipid bilayer without assistance.

False. Ions require transport proteins to cross the membrane.