1. Cells : The Units of Life

2. The Cell Theory

3. 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 ”

4. 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

5. 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

6. 150-200 Year Gap??? Between the Hooke/Leuwenhoek discoveries and the mid 19 th 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

7. 19 th Century Advancement Much doubt existed around Spontaneous Generation Conclusively disproved by Louis Pasteur Pasteur: Ummm, I don’t think so!!! + = ?

8. 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.

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

10. 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)

11. 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)

12. 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.)

13. Parts of the Cell: Organelles

14. COMMON CELL TRAITS A cell is the smallest unit that is capable of performing life functions.

15. 2 Types of Cells

16. COMPARING CELLS The size & shape of a cell relates to its function. (job it does)

17. Prokaryotic Cells (proh KAYR ee yah tihk) cells without membrane- bound structures EX: bacteria pond scum

18. Eukaryotic Cells (yew KAYR ee yah tihk) cells with membrane- bound structures EX: animals, plants, fungi and protists

19. protects the cell gives shape is made of cellulose A cell wall is found in plants, algae, fungi, & most bacteria. CELL WALL

20. CELL MEMBRANE Outer covering, protective layer around ALL cells For cells with cell walls,the cell membrane is inside the cell wall Allows food, oxygen, & water into the cell & waste products out of the cell.

21. CYTOPLASM gelatin-like inside cell membrane constantly flows aka protoplasm

22. CYTOSKELETON scaffolding-like structure in cytoplasm helps the cell maintain or change its shape made of protein

23. NUCLEUS Directs all cell activities Contains instructions for everything the cell does These instructions are found on a hereditary material called DNA Usually the largest organelle

24. NUCLEAR MEMBRANE separates nucleus from cytoplasm controls movement of materials in & out of nucleus

25. NUCLEOLUS Aka “little nucleus” Found in the nucleus

26. CHROMATIN contains genetic code that controls cell made of DNA & proteins

27. CHLOROPLASTS Green organelles that make food found only in plant cells

28. CHLOROPHYLL A green pigment that gives leaves & stems their color Captures sunlight energy that is used to produce food called glucose Glucose is a type of sugar

29. MITOCHONDRIA Organelles that release energy from food This energy is released by breaking down food into carbon dioxide AKA the powerhouse b/c they release energy from food Some muscle cells have 20,000 mitochondria

30. RIBOSOMES Make proteins Float freely or attached to the endoplasmic reticulum (ER) Ribosomes are made in the nucleolus

31. ENDOPLASMIC RETICULUM A series of folded membranes that move materials (proteins) around in a cell like a conveyor belt Smooth ER – ribosomes not attached to ER Rough ER – ribosomes attached to ER

32. GOLGI BODIES (GAWL jee) Stacked flattened membranes Sort and package proteins

33. VACUOLES Temporary storage spaces Store food, water, waste

34. LYSOSOMES (LI suh sohmz) The word "lysosome" is Latin for "kill body." The purpose of the lysosome is to digest things. They might be used to digest food or break down the cell when it dies. Break down food molecules, cell wastes & worn out cell parts

35. FROM CELL TO ORGANISM Cell The basic unit of life Tissue Group of cells working together Organ Group of tissues working together Organism Any living thing made of 1 or more cells Organ System Group of organs working together

36. NAME THE ORGANELLE d. Mitochondria b. Chloroplast c. Golgi body a. Nucleus

37. 1- Nucleus 2- Chromosomes 3- Mitochondria 4- Ribosomes 5- Chloroplasts 6- Vacuoles 7- ER 8- Cell Membrane