Cell Transport Mechanisms Explained

This video lecture covers the structure and function of the cell membrane, including its components like phospholipids, proteins, and cholesterol. It explains the concepts of passive and active transport, detailing processes such as diffusion, facilitated diffusion, and osmosis. The lecture also discusses the effects of different tonicities on cells and introduces active transport mechanisms like protein pumps, endocytosis, and exocytosis.

What is the primary structure that makes up the cell membrane?

• Nucleic acids

• Proteins

• Carbohydrates

• Phospholipids

What property do the heads of phospholipids have?

• Hydrophilic

• Hydrophobic

• Lipophilic

• Lipophobic

What is the role of cholesterol in the cell membrane?

• To store genetic information

• To provide energy

• To stabilize the membrane

• To facilitate diffusion

Which process does not require energy?

• Active transport

• Exocytosis

• Facilitated diffusion

• Endocytosis

What is osmosis?

• Movement of solutes across a membrane

• Movement of water across a membrane

• Active transport of ions

• Transport of proteins into the cell

What happens to a cell in a hypotonic solution?

• It swells

• It shrivels

• It divides

• It remains the same

What does a hypertonic solution cause a cell to do?

• Swell

• Die

• Shrink

• Divide

Which of the following is a form of active transport?

• Protein pumps

• Osmosis

• Facilitated diffusion

• Simple diffusion

What is endocytosis?

• Export of materials out of the cell

• Movement of water into the cell

• Intake of materials into the cell

• Diffusion of solutes into the cell

Which process involves the movement of substances from low to high concentration?

• Diffusion

• Osmosis

• Active transport

• Facilitated diffusion