Cell Membrane & Cell Transport

Front

What is the cell membrane?

Back

The cell membrane is a biological barrier that separates the interior of a cell from its external environment, composed mainly of a phospholipid bilayer with embedded proteins.

Front

What is diffusion?

Back

Diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration until equilibrium is reached.

Front

What is equilibrium in the context of cell transport?

Back

Equilibrium occurs when the concentration of a substance is equal inside and outside the cell, resulting in no net movement of that substance.

Front

What is a hypertonic solution?

Back

A hypertonic solution has a higher concentration of solutes compared to the inside of the cell, causing the cell to lose water and shrink.

Front

What is a hypotonic solution?

Back

A hypotonic solution has a lower concentration of solutes compared to the inside of the cell, leading to water entering the cell and potentially causing it to swell.

Front

What is an isotonic solution?

Back

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

Front

What types of molecules can easily diffuse across the phospholipid bilayer?

Back

Small nonpolar molecules, such as oxygen and carbon dioxide, can easily diffuse across the phospholipid bilayer without assistance.

Front

What is facilitated diffusion?

Back

Facilitated diffusion is the process by which specific molecules are transported across the cell membrane via protein channels, without the use of energy.

Front

What is active transport?

Back

Active transport is the movement of molecules against their concentration gradient, requiring energy (ATP) to move substances from lower to higher concentration.

Front

What is osmosis?

Back

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