The Discovery of Cells
In the seventeenth century, Robert Hooke looked
at thin slices of cork under a microscope that he
had made from lenses. He observed small box-like
shapes inside the cork. He called the little boxes
that he saw cells.
Under the five kingdom system cells can be
divided into two basic types.
Prokaryotic cells - simple cells without
distinct membrane bound organelles or nucleus.
Eukaryotic cells - more complex with
membrane bound organelles and nucleus.
• Contains the chromosomes (genetic
information) for the cell.
• Controls the activities of the cell.
• Double membrane - outer membrane and
• Inner membrane is folded forming cristae.
• The interior contains an organic matrix
containing chemical compounds.
• Site of aerobic respiration.
Rough Endoplasmic Reticulum
• A membrane system of flattened parallel
cavities which are interconnected and covered
• An intracellular transport system.
• Consists of a stack of flattened cavities which
package substances produced by the cell into
• These vesicles can fuse with the cell
membrane (exocytosis) or become lysosomes
Plant Cell Walls
• The main component of plant cell walls is
• Cellulose molecules are arranged in bundles
• The function of the plant cell wall is to provide
strength and support the plant.
Prokaryotic organisms are commonly called
They are cells with a simple structure.
They have no membrane around the nucleus
and lack any membrane bound organelles.
Blue-green bacteria make their own food by