Unit 2: Cell Structure & Function

Based on

Compartmentalization

The process by which cells use membranes to organize different processes and maintain distinct internal environments.

Eukaryotic Cells

Cells that have membrane-bound organelles and internal membranes that create specialized structures.

Prokaryotic Cells

Cells that lack membrane-bound organelles and include structures like ribosomes, DNA, cell membrane, and cell wall.

Ribosomes

Molecular machines in all cells that synthesize proteins, made of ribosomal RNA and protein.

Endomembrane System

A group of membrane-bound organelles, such as the nuclear envelope, endoplasmic reticulum, Golgi apparatus, and lysosomes, that modify, package, and transport materials within the cell.

Phospholipid Bilayer

A double layer of phospholipids that forms the basis of the cell membrane, where hydrophobic tails face inward and hydrophilic heads face outward.

Fluid Mosaic Model

A model describing the structure of the cell membrane as a mosaic of various proteins that can move within a fluid lipid bilayer.

Selective Permeability

The property of biological membranes that allows some substances to pass through while restricting others.

Osmosis

The diffusion of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration.

Turgor Pressure

The pressure exerted by the vacuole against the cell wall in plant cells, important for maintaining cell structure.

Active Transport

The process that requires energy to move molecules against their concentration gradient, often involving protein pumps.

Concentration Gradient

A difference in the concentration of a substance across a space or membrane.

Vesicular Transport

Mechanisms such as endocytosis and exocytosis that move large substances into and out of cells using vesicles.

Osmoregulation

An organism's ability to control its internal solute composition to maintain water balance.

Water Potential

A measure of how freely water molecules can move in a solution, determined by solute concentration and pressure.