Cell Structure An hypothesis originally proposed that all organisms are composed of cells. Over time, the concept has withstood scientific confirmation to now encompass 3 principles in the Cell Theory: 1) All organisms are composed of 1 or more cells and the life process of metabolism and heredity occur within those cells 2) Cells are the basic units of organization of all organisms 3) Cells arise by the division of pre-existing cells

A generalized Eukaryotic cell

Structure of an animal cell

Structure of a plant cell

A generalized Prokaryotic cell

Relative size ranges Most cells are microscopic, although vertebrate egg cells are large enough to be seen with the naked eye. Prokaryotic cells are ~ 1 – 10 um in length Eukaryotic cells are ~ 10 – 100 um in size

Surface area per unit volume Small cells vs. Large cells

Nuclear ultrastructure

Supercoiling of DNA w/i chromosome

Endoplasmic reticulum

Protein Synthesis along the ER

The Golgi apparatus

How proteins are processed

Lysosome function

Ribosome structure

Mitochondrion structure

Chloroplast structure

Representative animal cell

Representative Plant cell

Structures of the Cytoskeleton

Microfilament

Microtubule structure

Intermediate filament

Centrioles

Molecular motor

Flagellum and cilium

The Central Vacuole of Plant cells

Primary and secondary plant cell walls

Glycocalyx of eukaryotic cell