RECAP BIOLOGICAL FACTS

Explain the postulates of the cell theory STEM_BIO1 1/12-Ia-c-1

Pre-Activity: Did You Know? What is the smallest unit of Life?

How many cells make up an average human being? Did You Know? How many cells make up an average human being? 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”

Did You Know? What cell type that can no longer regenerate once used up?

Did You Know? What type of cell can carry Oxygen and supplies it through the body?

Did You Know? What is the smallest cell in nature?

Did You Know? What is the biggest cell in nature?

The Cell Theory

Youtube video about Cell Theory Guide Question: What were the major discoveries leading to the creation of Cell Theory? What is the cell theory about?

Discovery of Cells 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 1673- Used a handmade microscope to observe pond scum & 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

1827-33 - Robert Brown R-noticed that pollen grains in water jiggled around called “Brownian motion” -discovered Robert Brown the nucleus Nucleus Human Cheek Cell

A botanist who concluded that all plants are made of cells. 1838 - Matthias Schleiden A botanist who concluded that all plants are made of cells. Typical Plant Cell

1839 - Theodor Schwann A zoologist who concluded that all animals are made of cells. Nerve Cells

“Omnis cellula e cellula”. 1855 - Rudolph Virchow A physician who did research on cancer cells and concluded “Omnis cellula e cellula”. “All cells are from other pre-existing cells.”

Based on the discovery of Cell, if you are a scientist how would you derive the Cell Theory?

All organisms are composed of one or more cells. The 3 Basic Components of the Cell Theory : 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 2. The cell is the basic unit of life in all living things. (Schleiden & Schwann)(1838-39)

3. All cells are produced by the division of preexisting cells 3. All cells are produced by the division of preexisting cells. (Virchow)(1858)

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 are produced by the division of preexisting cells. (Virchow)(1858)

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.)

STEM CELL RESEARCH The research started simple question “How can the various parts of the human body began forming and how may it be possible to replicate the processes.

Modern Cell Theory

Assignment: on Modern Cell Theory Modern Cell Theory contains 4 statements, in addition to the original Cell Theory: 1. The cell contains hereditary information(DNA) which is passed on from cell to cell during cell division. 2. All cells are basically the same in chemical composition and metabolic activities. 3. All basic chemical & physiological functions are carried out inside the cells.(movement, digestion,etc) 4. Cell activity depends on the activities of sub-cellular structures within the cell(organelles, nucleus, plasma membrane)

Historical Background: Robert Hooke -1665 – coined the term cell 2. Corti – 1772 – saw substance within the cell 3. Fontana -1781- used the term nucleolus 4. Robert Brown – 1831 – saw the nucleus 5. Dujardin – 1835 – used the term sarcode 6. Mattias Jacob Schleiden & Theodore Schwann -1839- cell doctrine

7. Strasburger – illustrated cell division 8. Hugo Von Mohl – 1846 – used the term protoplasm 9. Max Schulze – protoplasm as physical basis of life 10. Thomas Huxley – protoplasm as chemical basis of life 11. Rudolph Virchow – 1858 – cell generalization 12. Schimper –1883- used the term plastid.

13. Frederich Mischer – 1868- saw DNA in pus 14. Benda Altmann – coined the term mitochondria 15. Camilo Golgi –1898- Golgi bodies 16. John Dalton – 1900 -Neuron in owl 17. Palade – 1900 – ribosome

18. Porter – 1900 – Endoplasmic reticulum 19. Daniel Davson – 1900 – Cell membrane as sandwich like 20. Christian de Duze – Lysosome in rat

Application: Explain the Cell Theory in your own words How has the knowledge of Cell Theory help you understand life.

Some Parting Thoughts Humans are just an intricately designed community of cells, which must work together to survive The next time you will be asked what is the essence of life?