Unit 2: Passive vs Active Transport and Tonicity Flashcards

A set of vocabulary flashcards covering the mechanisms of passive and active transport, tonicity rules, and specific examples such as diffusion and protein pumps.

Tonicity

The principle in Osmosis where water moves from a high to low concentration; it requires focusing on water levels using the formula $100\% \text{ solution} = \text{solute} + \text{water}$.

Passive Transport

The movement of substances from high to low concentration (with/down the concentration gradient) which uses no energy; examples include diffusion, osmosis, and facilitated diffusion.

Active Transport

The movement of substances from low to high concentration (against/up the concentration gradient) which uses energy ($ATP$); examples include protein pumps, Endocytosis, and Exocytosis.

Simple Diffusion

A form of passive transport where small, uncharged molecules like Oxygen and Carbon dioxide go straight through the membrane with no helper.

Facilitated Diffusion

A form of passive transport that uses channel proteins to move large and charged molecules, such as Glucose (sugar), across the cell membrane.

Osmosis (Facilitated Diffusion)

A specific type of facilitated diffusion that uses a water channel protein known as an Aquaporin to transport water.

Aquaporin

The specific protein channel used to facilitate the movement of water across the cell membrane.

Protein Pump / Carrier Proteins

A type of active transport that uses carrier proteins to move molecules from low to high concentration, such as the $Na^+$ - $K^+$ PUMP or proton pump.

Endocytosis

An active transport process using a vesicle to take large amounts of food or liquid into the cell; examples include phagocytosis and pinocytosis.

Exocytosis

An active transport process using a vesicle to take large amounts of food or liquid out of the cell.