The Study of the cell Cell: the smallest unit that can carry on all of life’s processes

1. Unit 3: Cytology The Study of the cellCell: the smallest unit that can carry on all of life’s processes

2. CELL THEORY • A theory resulting from many scientists’ observations & conclusions

3. CELL THEORY2. All living things are made of1 or more cells. • Matthias Schleiden(botanist studying plants) • Theodore Schwann(zoologist studying animals) stated that all living things were made of cells Schwann Schleiden

4. CELL THEORY3. All cells divide & come from oldcells. (Virchow) Virchow

5. Ocular Lens Body Tube Nose Piece Arm Objective Lenses Stage Stage Clips Coarse Adj. Diaphragm Fine Adjustment Light Source Base Skip to Magnification Section

6. Magnification • To determine your magnification…you just multiply the ocular lens by the objective lens • Ocular 10x Objective 40x:10 x 40 = 400 So the object is 400 times “larger” Objective Lens have their magnification written on them. Ocular lenses usually magnifies by 10x

7. TOTAL MAGNIFICATION • Powers of theeyepiece (10X) multiplied by objective lenses determine total magnification.

8. Using a Microscope • Start on the lowest magnification • Don’t use the coarse adjustment knob on high magnification…you’ll break the slide!!! • Place slide on stage and lock clips • Adjust light source (if it’s a mirror…don’t stand in front of it!) • Use fine adjustment to focus

9. FROM CELL TO ORGANISM Tissue Group of cells working together Organ Group of tissues working together Organ System Group of organs working together Organism Any livingthing made of 1 or more cells

10. The 3 basic structures found in most cells: 1. Nucleus 2. Cytoplasm 3. Cell membrane

11. Eukaryotic Cellhttp://www-class.unl.edu/bios201a/spring97/group6/eukcell.jpg

12. Parts of Eukaryotic Cells Vesicles Endoplasmic Reticulum Nucleolus Golgi Complex Cytoplasm Ribosomes DNA Nucleus Cell Membrane Mitochondria

13. - Parts of Eukaryotic Cells

14. Cell membrane

15. CELL MEMBRANE (Plasma membrane) • Outer covering, protective layer around ALL cells • Allows food, oxygen, & water into the cell & waste products out of the cell.

16. CELL MEMBRANE (Plasma membrane) • The boundary of the cell…separates inside from outside of cell • Is Semipermeable Membrane: allows some substances into cell and keeps others out of cell.

17. CELL MEMBRANE (Plasma membrane) • Has a phospholipid bilayer. The lipid molecules are fluid and can move past one another in a fluid manner…also allows proteins to move and change in this layer thus scientist explain cell membrane and call it a Fluid Mosaic Model

18. Cell Membrane are made of a phospholipid bilayer

19. Phospholipids can form: BILAYERS -2 layers of phospholipids with hydrophobic tails protected inside by the hydrophilic heads. The PHOSPHOLIPID BILAYER is the basic structure of membranes. A Phospholipid Bilayer

20. 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

21. Parts of the nucleus • Nuclear envelope • Nuceolus • Nucleoplasm • chromosomes

22. Actual Cell Nucleus

23. NUCLEOLUS • Aka “little nucleus” • Found in the nucleus • Contains RNA and proteins for ribosome synthesis

24. CHROMATIN • contains genetic code that controls cell • made of DNA & proteins • Condenses to form chromosomes during cell division Made of DNA and proteins Parts include: 2 sister chromatids held together by the centrally located centromere

25. Cytoplasm • gelatin-like inside cell membrane • constantly flows • aka protoplasm • It contains the various organelles of the cell Contains the various organelles

26. Internal Organization: • Organelles= perform specific functions. • function like tiny organs, analogous to organs of a multicellular body.

27. Centrioles • Short cylinder near nuclear envelope • There generally are 2 at right angles to each other • They control cell division

28. 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, functions in lipid synthesis • Rough ER – ribosomes attached to ER, functions in producing proteins

29. RIBOSOMES • Make proteins • Float freely or attached to the endoplasmic reticulum (ER) • Ribosomes are made in the nucleolus and are small particles of RNA

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

31. 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

32. MITOCHONDRIA • Organelles that release energy from food (power house of cell) • This energy is released by breaking down food into carbon dioxide • the powerhouse b/c they release energy(ATP) from food

33. Folds of mitochodria are called: cristae Mitochondria

34. VACUOLES • Temporary storage spaces • Store food, water, waste

35. CYTOSKELETON • scaffolding-like structure in cytoplasm that gives cell its shape • helps the cell maintain or change its shape • made of protein microfilaments and microtubules

36. Microfilaments • Built from actin, a globular protein and function in support of cytoskeleton and localized contraction of cell

37. Microtubules • Found in cytoplasm of all eukaryotic cells and function in cell support

38. Microbodies • Various membrane bound organelles that contain specialized teams of enzymes for specific metabolic pathways • important types: • 1. peroxisomes: break down H2O2 and detoxify alcohol

39. Intermediate filaments • Size intermediate to microtubules and microfilaments. • Function in reinforcing cell shape

40. Cilia • Short hair like projections from the cell that by beating produce organized movement. • Found in the trachea

41. Flagella • Long whiplike organelle whose action produces movement.

42. Extracellular material • Found outside cell • Material secreted by cell into the cell matrix, ranging from saliva, to gastric juices, ext…

43. Transport through cell membranes • There are 5 basic mechanisms: • DIFFUSION • OSMOSIS • ACTIVE TRANSPORT • FILTRATION • ENDOCYTOSIS

44. Diffusion • Diffusion is the net movement of molecules (or ions) from a region of their high concentration to a region of their lower concentration.The molecules move down a concentration gradient.Ex oxygen diffuses from RBC to cells body

45. Diffusion of molecules

46. Osmosis = Water diffusion, moving “down” the gradient The net direction of osmosis depends on the solute concentrations on both sides. • Hypotonic = lower solute concentration • Hypertonic = higher solute concentration • Isotonic = equal concentrations on both sides of the membrane

47. Osmosis in Red Blood Cells

49. Osmosis / Dialysis

50. Active Transport • requires energy use to move materials up their concentration • Moves from an area of low concentration to an area of high concentration • Example: sodium-potassium pump • Ex nerve cells transport sodium ions to extracellular environment