Cell Biology and Membrane Dynamics

Flashcards covering cell discovery, structural components like the cell wall and membrane, and the processes of osmosis and diffusion.

Mosaic model

A model describing the cell membrane where molecules are arranged like tiles in a mosaic.

Cell wall

An additional rigid layer around the cell membrane in plant, fungi, and bacteria cells that helps them withstand environmental stresses.

Limit of resolution

The ability of the human eye to see two very close objects as separate and distinct, which is $0.1\,mm$ for the human eye.

Robert Hooke

The first person to observe a cell in 1665 using a self-designed microscope while examining a slice of cork.

Osmosis

The movement of water through a selectively permeable membrane from an area with more water and less solute to an area with less water and more solute.

Concentration gradient

A difference in the concentrations of particles of matter that causes them to intermix.

Diffusion

The net movement of particles from a higher to a lower concentration, which occurs even without a membrane.

Isotonic solution

A solution where the solute concentration of the extracellular medium is equal to the solute concentration of the intracellular medium.

Hypotonic solution

A solution where the solute concentration of the extracellular medium is less than the solute concentration of the intracellular medium.

Hypertonic solution

A solution where the solute concentration of the extracellular medium is greater than the solute concentration of the intracellular medium.

Cell membrane

An extremely thin structure, about $7$ to $10\,nm$ thick, composed of lipids and proteins.

Lipid bilayer

The structure of the cell membrane consisting of two layers of special fat molecules with water-attracting heads facing outwards and water-repelling tails facing inwards.

Fluid-mosaic model

The model explaining that the cell membrane is fluid because molecules can move sideways, flip, and rotate within the membrane.