Unit 4: Cell Membrane and Transport

Front

What is the function of the contractile vacuole in a cell?

Back

The contractile vacuole helps to regulate water balance by expelling excess water from the cell.

Front

Define endocytosis.

Back

Endocytosis is the process by which cells engulf external substances, bringing them into the cell.

Front

What role do phospholipids play in the cell membrane?

Back

Phospholipids form the basic structure of the cell membrane, creating a bilayer that is flexible and semi-permeable.

Front

What is osmosis?

Back

Osmosis is the movement of water molecules through a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Front

What happens to the movement of materials during diffusion when equilibrium is reached?

Back

The movement of materials stops when there is a balance of concentration on both sides of the membrane.

Front

What is facilitated diffusion?

Back

Facilitated diffusion is the process of passive transport of molecules across a cell membrane via specific transmembrane integral proteins.

Front

Explain the difference between active transport and passive transport.

Back

Active transport requires energy to move substances against their concentration gradient, while passive transport does not require energy and moves substances along their concentration gradient.

Front

What is the significance of membrane flexibility?

Back

Membrane flexibility allows cells to change shape, move, and interact with their environment effectively.

Front

What is a selectively permeable membrane?

Back

A selectively permeable membrane allows certain molecules to pass through while blocking others, maintaining homeostasis within the cell.

Front

Describe the process of exocytosis.

Back

Exocytosis is the process by which cells expel materials in vesicles that fuse with the cell membrane, releasing their contents outside the cell.