1. Get your notebook out, copy and answer the following questions (don’t use the book): Get your notebook out, copy and answer the following questions (don’t use the book): 1.What are the 3 main types of microscopes? 2.Which one(s) enable the greatest magnification? 3.What is the smallest unit of organization that has all of the characteristics of life? 4.Where do you find the prologue in a book – in the beginning or at the end?

2. Check (& correct) your answers! 1. What are the 3 main types of microscopes? 2. Which one(s) enable the greatest magnification? 3. What is the smallest unit of organization that has all of the characteristics of life? 4. Where do you find the prologue in a book – in the beginning or at the end? Light microscope, SEM (scanning electron microscope), and TEM (transmission electron microscope) SEM and TEM: Up to 500,000x Light microscopes only go to ~1,500x The cell In the beginning, Pro = “before” in Greek

3. The Story of Cells

4. What are cells? The Building Blocks of Life Remember: The cell is the smallest structural unit capable of performing life functions.

5. Examples of Cells Amoeba Plants Red Blood Cell Nerve Cell Bacteria

6. Cell Trivia The average human being is composed of around 100 Trillion individual cells!!! The average human being is composed of around 100 Trillion individual cells!!! The egg yolk from an ostrich egg is the largest cell. They are about a half foot long. The egg yolk from an ostrich egg is the largest cell. They are about a half foot long. It would take as many as 50 cells to cover the area of a dot on the letter “i” on your paper It would take as many as 50 cells to cover the area of a dot on the letter “i” on your paper Ostrich egg   Chicken egg

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

8. The Microscope! (pg 171) 1673- Anton von Leuwenhoek, invented the microscope and observed pond scum and discovered single celled organisms He called them “animalcules”He called them “animalcules” He also observed blood cells from fish, birds, frogs, dogs, and humansHe also observed blood cells from fish, birds, frogs, dogs, and humans Therefore, it was known that cells are found in animals as well as plantsTherefore, it was known that cells are found in animals as well as plants

9. The Compound Light Microscope Developed in the 1600’s Developed in the 1600’s Maximum magnification of 1,500x Maximum magnification of 1,500x Uses light to magnify specimens Uses light to magnify specimens

10. The Electron Microscope Developed in the 1930’s-1940’s Developed in the 1930’s-1940’s Maximum magnification of 500,000x Maximum magnification of 500,000x Uses a beam of electrons to magnify specimens Uses a beam of electrons to magnify specimens 2 types: 2 types: –SEM (scanning electron microscope)  Used to scan the surface of cells  3D image –TEM (transmission electron microscope)  Used to study the internal structures of cells

11. The Cell Theory (pg 172) Memorize this! 1. All organisms are composed of one (unicellular) or more cells (multi-cellular). 2. The cell is the basic unit of structure, function, and organization of organisms. 3. All cells come from pre-existing cells.

12. Let’s investigate the 3 rd idea: Where does life come from? Old Theory - Spontaneous Generation Old Theory - Spontaneous Generation –Life spontaneously happens: Life comes from non-life Examples: Examples: –Mice from cloth sacks and grains. –Maggots from rotting meat. REALLY?

13. Where does life come from? 1858- Rudolf Virchow, German physician, after extensive study of cellular pathology, concluded that cells must arise from preexisting cells. 1858- Rudolf Virchow, German physician, after extensive study of cellular pathology, concluded that cells must arise from preexisting cells. Biogenesis – Life can only be formed from existing life. We will be investigating this further when we cover Evolution (Ch. 14), for now just understand the main ideas, no dates or names necessary.

14. Two Types of Cells Prokaryotic Prokaryotic Eukaryotic Eukaryotic REMEMBER US

15. Types of Cells (p.173) 1. Prokaryotes = bacteria cells 1. Prokaryotes = bacteria cells –No true nucleus, not membrane bound –Nucleoid = unbound ball of DNA 2 Domains 2 Domains –Archaea = similar to 1 st forms on life on earth –Eubacteria = more closely related to eukaryotic cells

17. 2. Eukaryotes = plant & animal cells with a true membrane bound nucleus 2. Eukaryotes = plant & animal cells with a true membrane bound nucleus –Organisms made up of one or more cells –Membrane bound organelles –Organelles = well-defined structures, perform specific functions, usually surrounded by membrane –Larger than prokaryotic cells

19. Basic Parts of A Cell Plasma Membrane = cell membrane, barrier between outside & inside Plasma Membrane = cell membrane, barrier between outside & inside

20. Cytoplasm = Cytoplasm = –fluid (cytosol) –organelles inside the cell Nucleus = membrane bound organelle containing DNA Nucleus = membrane bound organelle containing DNA

21. Logic-based classification exercise You will get a yellow sheet that contains characteristics of both prokaryotic and eukaryotic cells You will get a yellow sheet that contains characteristics of both prokaryotic and eukaryotic cells Work with your partner, and your partner ONLY, to classify the characteristics listed Work with your partner, and your partner ONLY, to classify the characteristics listed Read the instructions carefully and complete the assignment in your notebook. (If you don’t finish, there is a digital copy on the HW page) Read the instructions carefully and complete the assignment in your notebook. (If you don’t finish, there is a digital copy on the HW page) Return yellow half sheet to the front at the end of class Return yellow half sheet to the front at the end of class