AP Bio Unit 2B (Unit 3 in APC) Cell Parts, Transport, Signaling

Front

What is an isotonic solution?

Back

An isotonic solution has the same solute concentration as another solution, resulting in no net movement of water across the cell membrane.

Front

What happens to red blood cells in a hypotonic solution?

Back

Red blood cells swell and may burst (lyse) due to the influx of water.

Front

What is the primary driving force behind diffusion?

Back

The concentration gradient, which is the difference in concentration of a substance across a space.

Front

How do small, nonpolar molecules interact with the lipid bilayer of a cell membrane?

Back

They easily pass through the membrane's lipid bilayer due to their nonpolar nature.

Front

What is active transport?

Back

Active transport is the movement of molecules across a membrane against their concentration gradient, requiring energy (ATP).

Front

Why is continuous active transport necessary in cells?

Back

Because diffusion constantly moves solutes in opposite directions, active transport maintains necessary concentrations of substances.

Front

What is a hypertonic solution?

Back

A hypertonic solution has a higher solute concentration than another solution, causing cells to lose water and shrink.

Front

What is a hypotonic solution?

Back

A hypotonic solution has a lower solute concentration than another solution, causing cells to gain water and swell.

Front

What role do transport proteins play in cell membranes?

Back

Transport proteins facilitate the movement of substances across the cell membrane, especially for polar or charged molecules.

Front

What is facilitated diffusion?

Back

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