Passive Transport
Does passive transport require energy?
No. It does not require cellular energy (ATP).
Does active transport require energy?
Yes, it requires ATP.
What type of transport is the sodium-potassium pump?
Active transport.
Why are macromolecules unable to move through transport proteins?
They are too large.
What is endocytosis?
Movement of materials into the cell using vesicles.
In which direction do molecules move during passive transport?
From high concentration to low concentration (down the concentration gradient).
In which direction does active transport move molecules?
Against the concentration gradient (low → high concentration).
What does the sodium-potassium pump move?
Sodium ions (Na⁺) and potassium ions (K⁺).
What structure is used during bulk transport?
Vesicles.
What is phagocytosis?
A cell surrounds, engulfs, and digests a large particle.
What is diffusion?
Movement of molecules from an area of higher concentration to lower concentration.
Why does active transport require energy?
Moving molecules against their natural direction requires energy.
Why does the sodium-potassium pump need ATP?
It moves ions against their concentration gradients.
What is exocytosis?
Movement of materials out of the cell using vesicles.
What is pinocytosis?
A cell takes in liquids or small particles using vesicles.
Why does passive transport not require energy?
Molecules naturally move down their concentration gradient.
What type of proteins are involved in active transport?
Transport proteins/pumps.
Why is the sodium-potassium pump important?
It helps maintain proper ion concentrations and cell function.
Give an example of when a cell might use exocytosis.
Releasing hormones, neurotransmitters, or waste products.
What is receptor-mediated endocytosis?
A selective process where receptors bind specific substances and bring them into the cell.
Compare simple diffusion and facilitated diffusion.
Explain the difference between active and passive transport.
Why can’t sodium and potassium simply diffuse across the membrane?
They are charged ions and require transport proteins to cross the hydrophobic membrane.
Compare exocytosis and endocytosis.
Compare the three types of endocytosis.