Cell Transport Mechanisms and Processes

Mrs. Patel explains cell transport mechanisms, including passive transport (diffusion, osmosis, facilitated diffusion) and active transport (requiring energy). She details how molecules move across cell membranes, focusing on concentration gradients and the role of proteins. The video also covers endocytosis and exocytosis for transporting large materials.

What is the main characteristic of passive transport?

• It requires energy.

• It involves the use of protein carriers.

• It moves substances from low to high concentration.

• It does not require energy.

In simple diffusion, molecules move from:

• Low concentration to high concentration.

• High concentration to low concentration.

• Inside the cell to outside the cell only.

• Outside the cell to inside the cell only.

Which of the following is NOT true about simple diffusion?

• It requires energy.

• It does not use protein carriers.

• It moves molecules until equilibrium is reached.

• It involves a concentration gradient.

Facilitated diffusion requires:

• Molecules to move against the concentration gradient.

• No concentration gradient.

• Energy in the form of ATP.

• Protein channels to assist molecule movement.

Why do glucose molecules need protein channels for transport?

• They are too small to pass through the membrane.

• They have a charge that prevents them from passing through.

• They are too large to fit between phospholipids.

• They require energy to move across the membrane.

Osmosis involves the movement of:

• Oxygen molecules.

• Calcium ions.

• Water molecules.

• Glucose molecules.

What is the role of aquaporins in osmosis?

• They provide energy for water movement.

• They act as channels for water to pass through the membrane.

• They prevent water from entering the cell.

• They pump water against the concentration gradient.

Active transport is characterized by:

• No energy requirement.

• Use of energy to move substances against the concentration gradient.

• Movement of substances from high to low concentration.

• Facilitated diffusion of water.

Which of the following is an example of active transport?

• Simple diffusion of oxygen.

• Osmosis of water.

• Facilitated diffusion of glucose.

• Calcium ion pumping in neurons.

Endocytosis and exocytosis are processes that:

• Are types of passive transport.

• Do not require energy.

• Move small molecules across the membrane.

• Involve the movement of large materials into and out of the cell.