Membrane Transport

Front

What is facilitated diffusion?

Back

Facilitated diffusion is a process by which substances move across a cell membrane with the help of transport proteins, without the use of energy, following their concentration gradient.

Front

What is active transport?

Back

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

Front

What is a phospholipid?

Back

A phospholipid is a type of lipid molecule that is a major component of cell membranes, consisting of a hydrophilic (water-attracting) 'head' and two hydrophobic (water-repelling) 'tails'.

Front

What is exocytosis?

Back

Exocytosis is a form of bulk transport in which materials are transported out of the cell in membrane-bound vesicles that fuse with the plasma membrane.

Front

What is endocytosis?

Back

Endocytosis is the process by which cells engulf substances from their external environment, bringing them into the cell within vesicles.

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.

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 molecules from high to low concentration.

Front

What role do transport proteins play in membrane transport?

Back

Transport proteins facilitate the movement of specific substances across the cell membrane, either passively (facilitated diffusion) or actively (active transport).

Front

What is the difference between passive and active transport?

Back

Passive transport does not require energy and moves substances along their concentration gradient, while active transport requires energy to move substances against their concentration gradient.

Front

What happens to a cell in a hypertonic solution?

Back

In a hypertonic solution, water moves out of the cell, causing the cell to shrink.