Substance Transport in Cells: Diffusion, Osmosis, and Active Transport

Vocabulary terms and definitions covering the mechanisms of substance transport, including diffusion, osmosis, and active transport, as described in the lecture notes.

Diffusion

The net (overall) movement of particles from an area of higher concentration to an area of lower concentration.

Concentration Gradient

The state formed when there is a high concentration of particles in one area and a low concentration in another; particles move "down" this gradient during diffusion.

Equilibrium

The state reached when molecules, such as spray molecules in a room, have spread out and are balanced across an area.

Respiration

A process inside cells where oxygen and glucose are used to transfer energy, producing waste products like carbon dioxide.

Osmosis

The net movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration.

Partially Permeable Membrane

Also known as a semi-permeable membrane, it is a membrane that allows some molecules through it and not others.

Active Transport

The movement of particles across a membrane against a concentration gradient (from an area of lower to an area of higher concentration) using energy.

Mitochondria

Organelles that are numerous in cells undertaking large-scale active transport because the process requires energy from respiration.

Phosphate Ions

Particles that enter plant root hair cells via diffusion because they are in a higher concentration in the soil than inside the cells.

Magnesium Ions

Particles that enter plant root hair cells from the soil via active transport, moving from an area of lower concentration to an area of higher concentration inside the cells.

10 minutes

The duration of time specified for Samira to smell burnt toast in her bedroom after it burns in the kitchen due to diffusion.