DEVELOPMENT OF THE CELL THEORY Contributers to the Cell Theory

Antonie van Leeuwenhoek lived from 1632 to 1723 He made and improved single lens microscopes He observed many kinds of living cells: Algae, Bacteria, Protozoa, and multi-celled organisms

Leeuwenhoek’s Microscope :

Drawings by Leeuwenhoek’s

Robert Hooke He Lived From 1635 to 1703 Made one of the best microscopes in the world for it’s time

Robert Hooke Looked at Cork His drawing: He saw little compartmentsand he called them “Cells” He Gave Cells Their Name

Robert Brown lived from 1773 to 1858 He was a Botanist First person to identify the Cell’s nucleus

These are Orchid leaves which he observed: Nucleus

Matthais Schleiden He lived from 1804 to 1881 Professor of Botany instead In 1838, he came up with the idea that all plants are made from cells

Theodor Schwann Nerve Cells Lived from 1810 until 1882 He Studied Muscle Cells, Nerve Cells and Yeast Cells Concluded that Animals are also made up from cells Nerve Cells

Rudolf Virchow Lived from 1821 until 1902. He was a medical doctor. He concluded that all cells come from other cells He pushed the idea that diseases usually result from problems with cells rather than from problems with other bigger parts of the body

3. Cells are the basic unit of life Together, Schleiden, Schwann and Virchow are given most of the credit for coming up with the CELL THEORY which states: 1. All living things are made from cells 2. All Cells are produced from other cells 3. Cells are the basic unit of life

1930’s- Electron Microscopes Electron microscopes which magnify things 100’s of thousands of times bigger allows us to identify many cell parts and jobs.

TEM- Transmission Electron Microscopes- focus electron beams through thinly sliced objects. Electrons that pass through are recorded on the other side of the slide. Chloroplast at 10,000x

SEM- Scanning Electron Microscopes- scatters electrons over the surface of an object. Electrons reflect into screen. Gives a 3-dimensional look. Red Cell, Platelet, White Cell at 2,000x

SEM- Fly(100x)

SEM- Steel (10,000)

Smaller parts in the cell TEM-10,000x

Classification of Cell Types. All cells have a cell membrane (boundry for the cell) and cytoplasm (gelatin like material inside).

Classification of cell types. Prokaryote = no nucleus or membrane bounds organelles (Bacteria)(Archaea) Eukaryote = have a nucleus and membrane bounds organelles (Animal) (Plant) and others. Prokaryotes have ribosomes

What are organelles? Specialized part of a cell having some specific function; cell organ

Prokaryote

Prokaryote

Eukaryotes Plant Cells Animal Cells

Plant Cells Have a Cell wall around the Membrane that gives them a regular shape (Like Bricks In A Wall):

Animal Cells Have No Cell wall around the Membrane they often have irregular shapes: Brain Cells Blood Cells

Some Single Cell Organisms have many special parts that allow them to do with just one cell the same things that most other creatures do with millions of cells: