Our journey begins here.

1. Our journey begins here. Simple to Complex – Life’s Levels of Organization

2. Microscopes! What technology allows us to visually study cells?

3. Discovering Cells:Chapter 3 Section 1 • First sighting of cells The Cell Theory

4. First discoverer of cells! • Robert Hooke was an English scientist who lived 1635 – 1703. • In 1665 he published a book entitled Micrographia, which showed his pioneering work with microscopes and other ideas about life cycles of mosquitoes and craters on the moon.

5. Think about what you could draw that would help you remember the important info. Hooke was one of the first people to observe cells. He used a compound light microscope to study various things.

6. Robert Hooke • In one of his first observation of thinly sliced cork, the dead cells of oak bark the small square shaped structures gave them the name “cells” because they reminded him of the small rooms monks lived in at a monastery.

7. Anton van Leeuwenhoek • Also in the 1600sAnton van Leeuwenhoek discovered little “animicules” (known as protists now)in pond water in 1674. He was also was the first to see bacteria (from scrappings from his own teeth and gums in 1683) under his homemade microscope. • He also was the first person to observe blood flow through capillaries, muscle cells in detail, and sperm cells of various animals. • Anton only spoke Dutch and could not publish his findings in Latin so he wrote Robert Hooke who published for him.

8. Anton van Leeuwenhoek • The microscope van Leeuwenhoek used is considered a simple light microscope because it contained one lens and used natural light to view objects. However his lenses we exquisitely made. • Over the next 200 years, scientists greatly improved microscopes by making higher quality lenses and creating the compound (two lens) light microscope.

9. 200 years later… Turn to a teammate and tell them what you recall about cell discovery so far! What kind of microscope was used at first a light or electron scope?

10. Mathias Schleiden a german botanist studied plants and found all plants are made of cells. 1838!

11. TheodoreSchwann, a zoologist, made similar observations in 1839, animals and saw thatall animals are made of cells. He also coined the word ‘metabolism.’ First to understand yeast fermentation.

12. Rudolph Virchow, a doctor,observed that new cells only come from existing cells omnis cellula e cellula ("every cell stems from another cell"). The process of cell division is called mitosis. First to realize all disease results from cells not functioning properly.

13. The work of these last three men led to…

14. CELL THEORY Proposed in the 1800s by at least three different German scientists. Theory: • All living things are made up of cells. • Cells come from other cells. • Cells are the basic unit of life.

16. Modern cell theory adds three more statements: Cells contains hereditaryinformation which is passed from cell to cell during cell division. All cells are basically the same in chemicalcomposition. All energy flow (metabolism & biochemistry) of life occurs within cells.

17. More History of Cell Discovery 1595 – Jansen credited with 1st compound microscope.1655 – Hooke described ‘cells’ in cork. 1668 – Redi, performed an experiment to see if rotting meat changed into flies. He discovered that only flies to could make more flies, thus disproving the theory of spontaneous generation.1674 – Leeuwenhoek discovered protozoa. He saw bacteria some 9 years later.1833 – Brown described the cell nucleus in cells of the orchid.1838 – Schleiden and Schwann proposed cell theory-they however said cells spontaneously generated like mineral crystals.1840 – Albrecht von Roelliker realized that sperm cells and egg cells are also cells.1856 – N. Pringsheim observed how a sperm cell penetrated an egg cell.

18. 1855 – Remak discovers a method to isolate the membrane of the cell and proves that it divides a cell. 1858 –states his famous conclusion: omnis cellula e cellula, that is cells develop only from existing cells [cells come from preexisting cells]1857 – Kolliker described mitochondria.1879 – Flemming described chromosome behavior during mitosis by using dyes to stain cells.1898 – Golgi described the golgi body.1938 – Behrens used differential centrifugation to separate nuclei from cytoplasm.1939 – Siemens produced the first commercial transmission electron microscope. 1952 – Gey and coworkers established a continuous human cell line-without needing to take fresh tissue samples. 1955 – Eagle systematically defined the nutritional needs of animal cells in culture.

19. 1966 –Margulis endosymbiotic theory says that mitochondria and chloroplast were originally bacteria integrated into a eukaryotic. Cambridge Instruments produced the first commercial scanning electron microscope.1976 – Sato and colleagues publish papers showing that different cell lines require different mixtures of hormones and growth factors in serum-free media.1981 – Transgenic (from different species) mice and fruit flies are produced. Mouse embryonic stem cell line established.1995 — Publication of the first complete genome of a free- living organism. 1996 — Dolly the sheep was first clone of an adult mammal. 2002 — First virus produced 'from scratch', an artificial polio virus. 2010 — scientists for the first time have created a synthetic cell.