Cell membrane and Diffusion

Front

What is the structure of the cell membrane?

Back

The cell membrane is primarily composed of a phospholipid bilayer, with embedded proteins, cholesterol, and carbohydrates that help regulate what enters and exits the cell.

Front

What does hydrophobic mean in the context of the cell membrane?

Back

Hydrophobic refers to the 'water-fearing' nature of the fatty acid tails in the phospholipid bilayer, which prevents water-soluble substances from easily passing through.

Front

What is passive transport?

Back

Passive transport is the movement of substances across a cell membrane without the use of energy, moving from an area of high concentration to an area of low concentration.

Front

What is diffusion?

Back

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

Front

What is facilitated diffusion?

Back

Facilitated diffusion is a type of passive transport that uses protein channels to help move substances across the cell membrane.

Front

What is active transport?

Back

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

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

What is the concentration gradient?

Back

The concentration gradient is the difference in the concentration of a substance across a space, which drives the movement of particles during diffusion.

Front

What role do proteins play in the cell membrane?

Back

Proteins in the cell membrane serve various functions, including acting as channels for transport, receptors for signaling, and enzymes for biochemical reactions.

Front

What is the significance of cholesterol in the cell membrane?

Back

Cholesterol helps to stabilize the fluidity of the cell membrane, making it less permeable to very small water-soluble molecules that might otherwise pass freely through.