Structures of Eukaryotic Cells and Their Functions

 

Typical Animal cell

animalcell

 

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)

RanunculusRootCortex.jpg

Neuron.gif

 

Electron Microscopy - mitochondrion

mitochondria.gif