Biology Topic 2 - Molecules and Movement

Diffusion

the net movement of particles from a region of high concentration to low concentration (passive process)

Active Transport

the uptake of molecules or ions from a region of low concentration to high concentration across a selectively permeable cell membrane (active process)

Osmosis

movement of water from area of high concentration to low concentration through a semi-permeable membrane

Turgid

cell with a lot of water

Flaccid

cell with not enough water

Monomer

smaller basic unit

Polymer

multiple monomers in a chain

Enzyme

protein that functions as a biological catalyst

Enzyme-substrate complex

when enzyme and substrate are locked in together

Denatured

active site has changed shape

Active site

The part of the enzyme to which a specific substrate can attach or fit on to

lock and key hypothesis

substrate must be specific to enzyme like a lock and key

substrate

the specific molecule or substance upon which an enzyme acts

metabolic reactions

reactions that take place in cells

Catalyst

Thing that speeds up reaction but does not get used up/changed in reaction

Plasmolysed

A cell that has lost water, causing the cell membrane to pull away from the cell wall

Lysis

When a cell bursts open because its membrane breaks