Cell Membrane Structure and Functions

What are the main components of cell membranes?

• Phospholipids

• Proteins

• Carbohydrates

• Nucleic acids

What is the average thickness of the cell membrane?

• 20-40 nm

• 60-100 nm

• 100-120 nm

• 150-200 nm

What is the process by which water passes through the cytoplasmic membrane?

• Diffusion

• Osmosis

• Facilitated diffusion

• Active transport

What are the two basic mechanisms for the transfer of substances into and out of cells?

• Passive transport and active transport

• Diffusion and osmosis

• Endocytosis and exocytosis

• Facilitated diffusion and osmosis

What is the role of membrane proteins?

• Transport of ions

• Receptors for hormones

• Enzymatic activity

• All of the above

What is pinocytosis?

• Transport of solid particles

• Transport of soluble substances

• Transport of ions

• Transport of gases

What happens to cells in a hypertonic solution?

• They swell

• They shrink

• They remain the same

• They burst

What is the function of the Na+-K+ pump?

• Transport of glucose

• Regulation of ion concentration

• Facilitated diffusion

• Endocytosis

What is exocytosis?

• Transport of gases out of the cell

• Transport of ions out of the cell

• Transport of soluble substances out of the cell

• Transport of solid particles out of the cell

Which type of transport does not require energy?

• All of the above

• Endocytosis

• Facilitated diffusion

• Active transport