STPM Biology Structure of Cell and Organelle (Part 2)

Cell

Definition: Cell is the basic structural and functional unit in living organisms.

Eukaryotic cells

• cells with a membrane enclosed nucleus and membrane enclosed organelles.
• cells of plants, animals, fungi and protozoas are all eukaryotic cells.
• Eukaryote = an organism possessing eukaryotic cells.

Basic structures of eukaryotic cell

Prokaryotic cells

• cells without a membrane enclosed nucleus and membrane enclosed organelles.
• bacterial cells are prokaryotic cells.
• Prokaryote = an organism possessing prokaryotic cells.

Basic structures of prokaryotic cell

 
Common measurement units used for cells are μm (micrometer) and nm (nanometer).

1μm = 10^-6m

1nm = 10^-9m