Why should we study cells? Cells introduction video

Cells are important to study, because they make up every living organism on the planet! Have you ever been ill? Even if it was a ‘tummy bug’ it will have been your cells that were affected by the poisonous chemicals or toxins from bacteria cells in the bad food. You may know of someone who has been ill with a disease or disorder such as meningitis, malaria, diabetes, a type of cancer, cystic fibrosis, or Alzheimer’s disease. All these diseases and disorders are caused by problems at a cell or molecular level. Physical damage such as a burn or broken bone also causes damage at cell level. By understanding how cells work in healthy and diseased states, cell biologists working in animal, plant and medical science will be able to develop new vaccines, more effective medicines, plants with improved qualities and through increased knowledge a better understanding of how all living things live.

DNA testing has been used in archaeology to provide evidence that a living person is related to a long dead ancestor. Richard III Forensic medicine uses cell biology and DNA fingerprinting to help solve murders and assaults. Neither the courts of law nor the criminals can escape the importance of cell biology.

Biotechnology uses techniques and information from cell biology to genetically modify crops to produce alternative characteristics to clone plants and animals to produce and ensure high quality food is available at lower costs Golden Rice to produce purer medicines and in time organs for the many people who need transplants. Cell biology is about all this and can make an exciting career.

The Cell Theory COPY

Some Random Cell Facts The average human being is composed of around 100 Trillion individual cells!!! It would take as many as 50 cells to cover the area of a dot on the letter “i”

Old Beliefs Spontaneous Generation (also called ‘abiogenesis’) COPY Old Beliefs Spontaneous Generation (also called ‘abiogenesis’) The idea that non living things could generate life. This belief follows easily from observations: How do fruit flies suddenly appear?

. . . Spontaneous Generation This lead to many (strange to us now) beliefs: That rotten meat made maggots That mice were formed from dirty rags That fish were formed from rotting leaves at the bottom of ponds That sweat made lice That eels were formed from mud COPY

. . . Spontaneous Generation COPY Three scientists helped to refute the idea of spontaneous generation Francesco Redi (1628-1697) an Italian doctor Lazzaro Spallanzani (1729-1799) an Italian scientist Louis Pasteur (1822-1895) a French scientist

Francesco Redi, 1668 Redi put fresh meat into 3 jars. COPY Francesco Redi, 1668 Redi put fresh meat into 3 jars. He sealed the first one, he left the second one open, and he covered the opening of the third with some netting. As the meat rotted, he observed no flies or maggots on the meat in the first jar many flies and maggots on the meat of the second jar Flies and maggots on the netting of the third jar

COPY Lazarro Spallanzani He wanted to support Redi’s findings. He was very close to disproving spontaneous generation. What did he do wrong?

Louis Pasteur Have you ever heard of pasteurization? (He’s the scientist who discovered it!) Bill Nye- Spontaneous Generation

Pasteur’s Experiment: COPY

COPY Example: Changing people’s belief’s that the world was flat is a paradigm shift. Redi, Spallanzani and Pasteur all contributed to a paradigm shift about where life comes from.

Discovery of Cells COPY 1665- English Scientist, Robert Hooke, discovered cells while looking at a thin slice of cork. He described the cells as tiny boxes or a honeycomb He thought that cells only existed in plants and fungi

Anton van Leuwenhoek COPY 1673- Used a handmade microscope to observe pond scum & teeth scrapings. He discovered single-celled organisms He called them “animalcules” He also observed blood cells from fish, birds, frogs, dogs, and humans Therefore, it was known that cells are found in animals as well as plants

150-200 Year Gap??? Between the Hooke/Leuwenhoek discoveries and the mid 19th century, very little cell advancements were made. This is probably due to the widely accepted, traditional belief in Spontaneous Generation. Examples: -Mice from dirty clothes/corn husks -Maggots from rotting meat

Development of Cell Theory 1838- German Botanist, Matthias Schleiden, concluded that all plant parts are made of cells 1839- German physiologist, Theodor Schwann, who was a close friend of Schleiden, stated that all animal tissues are composed of cells.

Development of Cell Theory 1858- Rudolf Virchow, German physician, after extensive study of cellular pathology, concluded that cells must arise from preexisting cells.

The Cell Theory Complete COPY The Cell Theory Complete The 3 Basic Components of the Cell Theory were now complete: 1. All organisms are composed of one or more cells. (Schleiden & Schwann)(1838-39) 2. The cell is the basic unit of life in all living things. (Schleiden & Schwann)(1838-39) 3. All cells come from preexisting cells. (Virchow)(1858)

Modern Cell Theory Modern Cell Theory contains 4 statements, in addition to the original Cell Theory: The cell contains hereditary information(DNA) which is passed on from cell to cell during cell division. All cells are basically the same in chemical composition and metabolic activities. All basic chemical & physiological functions are carried out inside the cells.(movement, digestion,etc) Cell activity depends on the activities of sub-cellular structures within the cell(organelles, nucleus, plasma membrane)

How Has The Cell Theory Been Used? The basic discovered truths about cells, listed in the Cell Theory, are the basis for things such as: Disease/Health/Medical Research and Cures (AIDS, Cancer, Vaccines, Cloning, Stem Cell Research, etc.)

Some Parting Thoughts It is amazing to think that the cells that make up our bodies are just as alive as we are. Humans are just an intricately designed community of cells, which must work together to survive.