Structures of Eukaryotic Cells and Their Functions

Typical Animal cell

I. Membrane-bound organelles

Structure	Description & Function	Found in Animals?	Found in Plants?
Plasma Membrane	Membrane boundary of cell; regulates cell transport	X	X
Nucleus	Large structure surrounded by double membrane; species cellular proteins	X	X
Nucleolus	Granular body within nucleus; site of r-RNA synthesis	X	X
Endoplasmic reticulum	Network of internal membranes; site of membrane lipid & protein synthesis	X	X
Golgi Complex	Stacks of flattened membrane sacs; modifies, packages & secretes proteins	X	X
Lysosomes	Membranous sacs; contains enzymes to digest materials	X	X
Vacuoles	Membranous sacs; transport and store water & other materials	X	X
Mitochondria	Sacs containing 2 membranes; site of Krebs cycle, electron transport system, chemiosmosis.	X	X
Plastids	Sac-like structures with internal thylakoid membranes; photosynthesis		X
Microbodies	Membranous sacs containing enzymes, diverse reactions	X	X

II. Particulate Structures

Structure	Description & Function	Found in Animals?	Found in Plants?
Chromosomes	Composed of DNA-protein complex; contains genes	X	X
Ribosomes	Granular organelles composed of RNA & protein; synthesize proteins	X	X
Microtubules	Hollow tubes of tubulin; structural support for organelles of movement	X	X
Microfilaments	Solid, rodlike structures of actin, structural support	X	X
Centrioles	Small hollow cylinders; involved in cell division & anchors flagellae & cilia	X
Cilia	Short hair-like structures; movement, food intake, usually >>1 on a cell.	X	X
Flagella	Long projections; cellular locomotion, usually 1-5 on a cell.	X	X

III. Extracellular structures

Structure	Description & Function	Found in Animals?	Found in Plants?
Cell wall	Multiple-layers of cellulose; structural support		X

What we can see is limited by the equipment we have available

Light Microscopy
Plant cells (Ranunculus, i.e. buttercup root)	Animal cell (Neuron)

Electron Microscopy - mitochondrion