The Structure of Cells. What is a cell?? - The smallest functional unit of life. The Discovery of Cells. Robert Hooke, 1665, observed a slice of cork under a primitive microscope Anton van Leeuwenhoek observed living blood cells, bacteria, and tiny single-cell organisms in a drop of water.
What is a cell??
- The smallest functional unit of life.
How big is a cell?
If 1000 human body cells were lined up, they would be less than 2 cm long – about as wide as your thumb!
The Evolution of Organelles
macromolecules into a form that can
be used by the cell: ATP - adenosine triphosphate