2. CELLS & the ORGANELLES Prokaryote vs. Eukaryote Animal vs. Plant

3. Early Microscopes Robert Hooke (1665)  Coined the term “cell” (Why?)  looking at cork, he saw little boxes  Is cork alive? Anton von Leeuwenhoek (1674)  saw living cells in pond water

4. Cell Discoveries Matthias Schleiden (1838)  Plants are made of cells Theodor Schwann (1839)  Animals are made of cells Rudolf Virchow (1855)  Saw dividing cells  new living cells come from pre-existing cells

5. The Cell Theory 1. All living things made of cells. 2. Cell are the basic unit of structure & function for life. 3. Cells can only arise from pre-existing living cells  

6. Specialization Unicellular organisms  living organisms that are only ONE cell –Examples: bacteria, algae, protists, yeast Multicellular organisms  any organism that is made of more than one cell –Evolved later

7. Kingdoms and Domains Three Domain System (based on rRNA evidence) Six Kingdom System (based on rRNA evidence) Traditional Five Kingdom System BacteriaArchaeaEukarya BacteriaArchaeaPlantaeProtistaFungiAnimalia MoneraProtistaPlantaeFungiAnimalia Humans = 5%

8. Prokaryote vs. Eukaryote All cells have a membrane, cytoplasm, DNA & ribosomes Prokaryotic Cells –DNA not bound by a membrane… no “true nucleus” –Usually smaller, simple –No membrane bound parts (organelles) –Ex: bacteria Eukaryotic Cells –Membrane bound nucleus –Larger, complex, internal organization –Have internal membrane bound structures –Ex: you, plants, algae

10. Can unicellular organisms be eukaryotic? What does that mean? Do prokaryotes have DNA? What is an example of a prokaryote? Are prokaryotes considered to be alive?

11. Why do we need to understand cells? Each organelle has a specific job that needs to be performed. The more we understand their jobs, the better we can understand life.

12. Basic Cell Structures Cell membrane Nucleus -nucleolus -nuclear envelope Cytoplasm

13. Organelles Very small size Can only be observed under a microscope Have specific functions Found throughout cytoplasm Include: Cytoplasm, Nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, mitochondria, chloroplasts (plants only), cytoskeleton, centrioles (Animal only)

14. The Nucleus: Control center of the cell, houses genetic material

15. Nucleolus Is a small dense region in the nucleusIs a small dense region in the nucleus Makes ribosomes, which make proteinsMakes ribosomes, which make proteins

16. RIBOSOMES Free floating in cytoplasm or Attached to ER “reads” RNA code from DNA to assemble proteins “protein factory”

17. ENDOPLASMIC RETICULUM Internal membrane Lipid parts of the cell membrane made here Makes proteins etc. for shipment out of cell Can be “Rough” or Smooth

18. GOLGI APPARATUS Modifies, sorts, packages proteins and other products Destination – storage in cell – export out of cell Customizes Adds lipids, carbs to protein

19. LYSOSOMES Small, enzyme-filled organelles Digests material for use or disposal Tay Sachs disease has dysfunctional lysosomes in neural cells which allows fats to accumulate

20. MITOCHONDRIA Convert food into usable energy Have an outer & inner membrane Has its own DNA! –Inherited from your mom

21. CHLOROPLASTS Capture sunlight & convert it to energy –Photosynthesis Have 2 membranes Contain the green pigment chlorophyll Has its own DNA!

22. VACUOLES Stores materials Water, salts, protein, carbs Largest in plants –Gives turgor pressure May not be present in animals

23. CYTOSKELETON Structural support & transport MICROFILAMENTS Actin – threadlike protein MICROTUBULES Tubulins – protein basis of cilia & flagella

24. CENTRIOLES Help in the process of cell division Only in Animals

25. PLANTS V. ANIMALS CELL WALLS LARGE VACUOLE CHLOROPLASTS CENTRIOLES NO central VACUOLE NO CHLOROPLASTS

26. Awesome cell clip http://www.youtube.com/watch?v=kxSLw1 LMvgkhttp://www.youtube.com/watch?v=kxSLw1 LMvgk

27. Cooperation Among Cells UNICELLULAR: Each individual cell is its own organism, but may form: - Colonies – Volvox, colonial algae - Biofilms – Bacteria on teeth, plaque What are the advantages of cooperating? Disadvantages? MULTICELLULAR Cells are specialized (specific roles) - eventually form tissues  organs  systems What are our specialized cell types?

28. Volvox http://www.youtube.com/watch?v=-V7LTyJuAy4&feature=related http://www.youtube.com/watch?v=-V7LTyJuAy4&feature=related

29. Colonies of Bacteria

30. Cell to Cell Connections Cells in same tissue communicate with each other through junctions –Tight junction : membranes are fused, stitched together; no passage –Desmosomes: protein fibers that anchor in cytoplasm of neighboring cells – allow passage of materials –Gap junction : Channels formed by donut-shaped proteins btwn cells ; yes passage –Pits & Plasmodesmata : (plants) cell walls perforated with pits, strands of cytoplasm (plasmodesmata) run through pits connecting cells

31. Can you find the connection?

33. Extracellular Matrix Solution of macromolecules (proteins & carbs) that surround cells in a tissue –Secreted by the cell itself to the space outside Holds cells together Allows them to migrate & interact May regulate behavior in cells Ex: collagen

34. Question You are not feeling well so you go to the doctor. She swabs your throat and grows the bacteria in the lab to identify. She discovers that it is Streptococcus pneumoniae, a common but harmful bacteria. When she looks in her microscope, does she see a nucleus in this organism? Why or why not?

35. Question You got a bad rash at sports camp. The doctor has prescribed you a cream that she says will help break down the cell wall of the organism that is growing on your skin. Do you have a bacterial infection or a fungal infection? Or do you need more information? Will this cream injure your skin cells in the same way? Why or why not?

36. Question Trace the path of protein production from DNA to export.