Cell Membrane and Transport

Front

What is a phospholipid?

Back

A phospholipid is a molecule composed of a phosphate and glycerol head and two fatty acid chain tails, which forms the basic structure of cell membranes.

Front

What does 'bilayer' refer to in the context of cell membranes?

Back

'Bilayer' refers to the arrangement of phospholipids in the cell membrane, where two layers of phospholipids are aligned with their hydrophilic heads facing outward and hydrophobic tails facing inward.

Front

What is the difference between active transport and passive transport?

Back

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

Front

What is a hypotonic environment?

Back

A hypotonic environment is one where the concentration of water is higher outside the cell than inside, causing water to enter the cell and potentially leading to cell bursting.

Front

What is diffusion?

Back

Diffusion is the movement of particles from an area of high concentration to an area of low concentration until equilibrium is reached.

Front

What is osmosis?

Back

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

Front

What is the role of transport proteins in the cell membrane?

Back

Transport proteins facilitate the movement of substances across the cell membrane, either by passive transport (without energy) or active transport (with energy).

Front

What is the function 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.

Front

What is a hypertonic environment?

Back

A hypertonic environment is one where the concentration of solutes is higher outside the cell than inside, causing water to leave the cell and leading to cell shrinkage.

Front

What is facilitated diffusion?

Back

Facilitated diffusion is a type of passive transport that uses transport proteins to help move molecules across the cell membrane without the use of energy.