Biology TEKS 4.B: Cell Transport

Front

What is cell transport?

Back

Cell transport refers to the movement of substances across the cell membrane, which can occur through passive or active mechanisms.

Front

Define passive transport.

Back

Passive transport is the movement of molecules across the cell membrane without the use of energy, relying on concentration gradients.

Front

What is active transport?

Back

Active transport is the movement of molecules against their concentration gradient, requiring energy (usually in the form of ATP).

Front

Explain diffusion.

Back

Diffusion is the process by which molecules spread from areas of high concentration to areas of low concentration until equilibrium is reached.

Front

What is osmosis?

Back

Osmosis is the diffusion of water molecules across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration.

Front

Define isotonic solution.

Back

An isotonic solution is one where the concentration of solutes is equal inside and outside the cell, resulting in no net movement of water.

Front

What is a hypertonic solution?

Back

A hypertonic solution has a higher concentration of solutes outside the cell than inside, causing water to move out of the cell, leading to cell shrinkage.

Front

Define hypotonic solution.

Back

A hypotonic solution has a lower concentration of solutes outside the cell than inside, causing water to move into the cell, which may lead to cell swelling or bursting.

Front

What role do transport proteins play in cell transport?

Back

Transport proteins facilitate the movement of substances across the cell membrane, either by providing a passageway for passive transport or by actively moving substances against their gradient.

Front

Explain the concept of selective permeability.

Back

Selective permeability is the property of cell membranes that allows certain molecules to pass through while blocking others, maintaining homeostasis.