Cell structure

Cell Theory

A scientific theory stating that all living things are made up of cells, the cell is the basic unit of life, and all cells come from pre-existing cells.

Unicellular

Organisms made up of one cell.

Multicellular

Organisms made up of multiple cells.

Eukaryote

Organisms composed of cells with membrane-bound organelles, can be unicellular or multicellular.

Prokaryote

Unicellular organisms that do not have membrane-bound organelles.

Organelles

Substructures found inside cells that perform specialised functions.

Cell Membrane

A phospholipid sac that protects the cell and allows for selective permeability.

Cytosol

A gel-like solution inside the cell membrane that houses organelles.

Nucleus

A large membrane-bound structure that contains the organism's DNA and regulates gene expression.

Nucleolus

A small organelle within the nucleus that produces specialized RNA.

Ribosomes

Structures made of protein and RNA that produce proteins.

Endoplasmic Reticulum

A network of membranes that transports substances around the cell; can be rough (with ribosomes) or smooth (without ribosomes).

Mitochondria

Bean-shaped organelles that carry out cellular respiration to produce energy.

Golgi Apparatus

A stack of membrane sacs that receives, sorts, and dispatches substances in vesicles.

Lysosomes

Small sacs filled with enzymes that digest large molecules and foreign invaders.

Apoptosis

The natural process of cell death.

Necrosis

Abnormal cell death.

Centrioles

Cylindrical structures that assist in cell division.

Vacuoles

Membrane-bound spaces that store water, salts, and nutrients, contributing to cell support.

Cell Wall

A rigid structure surrounding the cell membrane in some organisms, providing protection and support.

Chloroplast

A double-membraned organelle where photosynthesis occurs, containing chlorophyll.

Cell Wall in Plants

Made of cellulose, a rigid polysaccharide that protects the cell.

Polysaccharide

A chemical made of multiple covalently bonded sugar units.

Cellulose

A polysaccharide composed of repeated subunits of B-glucose.