Cell Lecture #1

What Are Cells?

History of Cells

What is a Cell?

A cell is the basic unit of structure and function in living things.

Invention of microscope made seeing cells possible

History of Cell Discovery

Robert Hooke gets credit for discovering cells by looking at cork - he thought they looked like “prison cells”

Anton van Leeuwenhoek

This Dutch scientist discovered little things swimming in pond water which he called “animalcules” (little animals) with microscopes he made himself

Three parts to the Cell Theory

1. All living things are made of cells

2. All cells come from other cells

3. The cell is the basic unit of structure and function in living things

Early Cell Scientists

1.Matthias Schleiden discovered that all plants were made of cells in 1835

2. Theodore Schwann discovered that all animals were made of cells in 1836

Early Cell Scientists (cont)

3. Rudy Virchow discovered that all cells come from other cells in 1855; His rule - Omnis cellula e cellula ("every cell originates from another cell")

Main Types of Microscopes

Light microscopes bend light rays through convex lenses. They are powerful because you multiply the powers of each lens to get total magnification

Electron Microscopes

Electron Microscopes use a focused beam of electrons instead of light allowing for much increased magnification. Unfortunately it kills the specimen if it is alive.

Scanning Electron Microscope Pics