1. Unit 4

2. Discovery of Cells Anton van Leeuwenhoek : Made improvements to the simple microscope in 1648 –Saw microscopic critters in pond water 1674

3. Discovery of Cells Robert Hooke 1 st person to see cells & identify them – saw cell walls in cork 1665; He gave ‘cells’ their name!

4. Discovery of Cells Theodor Schwann – said all animals are made up of cells Matthias Schleiden – said all plants are made of cells

5. Discovery of Cells Rudoph Virchow Said all cells come from other cells – 1855 – He completed the Cell Theory

6. Cell Theory Ideas developed due to discoveries made after the invention of the microscope….The Cell theory states that: –All living things are composed of cells –Cells are the basic units of structure and function in living things –New cells are produced from existing cells

7. Types of Microscopes Compound Light Microscope : several lenses used to magnify objects up to 1000 times using light. We use these in class.

8. Types of Microscopes Dissecting Microscope: uses light but has a lower magnification; used to look at big objects like rocks, insects, and flowers

9. Types of Microscopes Electron Microscope: very high magnification; uses beam of electrons instead of lights –Can magnify 1000 times larger than compound microscope

11. 2 Types of Cells Prokaryotic Cells and Eukaryotes Cells

12. Prokaryotes The cell DOES NOT have a “true” nucleus; Tend to be smaller than Eukaryotes No MEMBRANE BOUND ORGANELLES – still have certain structures –Ex: All bacteria

13. Eukaryotes The cell HAS a “true” nucleus –Eukaryotes contain organelles which are membrane bound. The organelles are also specialized. –Ex: All plants, animals, fungi, & protists

14. Similarities and Differences in Prokaryotes and Eukaryotes Cell membrane Contain DNA Cytoplasm Ribosomes Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton EukaryotesProkaryotesBoth

16. Cell Organelles 1 1 Tiny structures inside the cell that perform functions The organelles are to the cell as the organs are to the whole body Cells  Tissues  Organs  Organ Systems  Organism

17. NUCLEUS The control center of the cell contains DNA, chromatin, & chromosomes DNA contains coded instructions needed to make proteins Chromosomes are thread- like structures that contain genetic material

19. Nucleolous The space inside of the nucleus where ribosomes are produced.

20. CYTOPLASM Gel-like material in the cell organelles are suspended in the cytoplasm

21. Ribosomes Makes proteins with the help of RNA and Amino Acids PROKARYOTE HAVE THESE AS WELL!

22. Endoplasmic Reticulum Moves materials around the cell Assembly of Lipids Assists with Protein Synthesis Rough ER: contains ribosomes Smooth ER: no ribosomes

23. Mitochondria : “ Power-house” of the cell makes ATP (energy); found in both plants, animals, protist, and fungi –Converts food into compounds that the cell uses for growth, development, and movement

24. Cell Respiration C 6 H 12 O 6 + O 2  H 2 O + CO 2 + ATP Glucose + Oxygen  Water + Carbon Dioxide + ATP Aerobic Respiration – Requires Oxygen & yields 36-38 ATPs per glucose molecule ----------------------------------------------------------------------- Anaerobic Respiration – No oxygen used; called Fermentation; Only 2 ATPs per glucose molecule; Lactic Acid build up – causes muscle burn in humans

25. Cell Respiration Plants, Animals, Fungi, Protists & Bacteria carry out Cell Respiration.

26. Chloroplasts : Converts energy from sunlight into chemical energy by photosynthesis –Found in plants and protist

27. Photosynthesis H 2 O + CO 2 + Sunlight  C 6 H 12 O 6 + O 2 Photosynthesis USES the products of Cell Respiration Cell Respiration USES the products of Photosynthesis

28. Photosynthesis Plants, Bacteria and Protists with chlorophyll (light energy absorbing pigments) can carry out Photosynthesis to make their own food using sunlight.

29. Golgi Apparatus Sorts & Packages proteins from the ER

30. Vacuole Stores water, salts, protein, & carbs –Plant cells have a single large vacuole (stores water) –Animal- like protist cells have many small vacuoles

31. Lysosomes : Contains enzymes to digest waste

32. Cytoskeleton helps the cell maintain its shape –Contains microfilaments & microtubules

33. Cilia and Flagella Both used for locomotion/feeding Flagella – long/whiplike Cilia – short/hair-like Prokaryotes have these as well!

34. Cell Wall Provides support and protection for the cell; found in plant, fungi, some protist, and bacteria cells

35. Regulates what enters and leaves the cell; found in ALL organisms –Composed of a Lipid bilayer (contains lipids and proteins) Cell Membrane

36. The Cell Membrane The cell membrane is the outer layer of animal cells and just inside the cell wall of plants. Animal Cell Plant Cell Cell Membrane Cell Wall

37. The cell membrane is a double layer of phospholipids called the phospholipid bilayer. The phospholipid bilayer is designed to protect the cell and regulate what enters and leaves the cell. The phospholipid bilayer is fluid and flexible. A phospholipid: DRAW THIS Hydrophilic Head Hydrophobic Tails

38. A phospholipid has a hydrophilic head and a hydrophobic tail. Hydrophilic means WATER LOVING (polar phosphate head) Hydrophobic means WATER HATING (non- polar lipid tails) The hydrophilic heads are on the outside of the cell and on the inside of the cell. The hydrophobic tails are stuck in the middle. DRAW THIS

39. Cholesterol is scattered throughout the membrane and acts like glue to hold it together. The cell membrane also contains proteins that are imbedded (stuck) in the membrane, so half of the protein is on the outside of the cell and half of the protein is on the inside of the cell. There are several types of proteins, each with its own special function. Carbohydrate chains are attached to the part of the protein on the outside of the cell. These carbohydrates act as flags and can help cells recognize one another. EX) liver cells have a specific type of carbohydrate chain EX) skin cells have a specific type of carbohydrate chain

40. Since the cell membrane is fluid and has several different molecules in it, it is called the fluid mosaic model. Phospholipid Bilayer cholesterol Protein Carbohydrate chain

42. Lipid Bilayer Outside of cell Inside of cell (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains

43. Plant Cell – more boxy shape; cell wall present & chloroplasts Vacuole Chloroplast Cell Membrane Cell Wall Golgi Apparatus Mitochondria Smooth Endoplasmic Reticulum Ribosome (free) Ribosome (attached) Nuclear Envelope Nucleolus Nucleus Rough Endoplasmic Reticulum

44. Animal Cell – rounder shape; no cell wall; no chloroplasts

45. Movement Into and Out of the Cell Membrane

46. Permeability The ability to allow certain gasses, liquids & other substances to pass through a barrier (like the cell membrane)

47. Types of Transport Passive Transport – Movement where energy is not required –Diffusion and Osmosis –Done to maintain equilibrium across a semi- permeable membrane (i.e. – cell membrane)

48. Diffusion Movement of molecules from an area of higher concentration to lower concentration –Does not require energy from the cell Solute Cell Membrane

49. Facilitated Diffusion Diffusion of large molecules through channel proteins embedded in the cell membrane –Does Not require energy from cell Molecules move from higher concentration to lower concentration High Concentration Low Concentration Cell Membrane Glucose molecules Protein channel

50. Osmosis Diffusion of water through a selectively permeable membrane Water moves from higher concentration to lower concentration

51. OSMOSIS

52. Effects of Osmosis on Cells SolutionEffect on Cell Hypertonic Solution has a higher solute concentration than the cell Water moves OUT of the cell (cell shrinks) Hypotonic Solution has a lower solute concentration than the cell Water moves INTO the cell (cell expands and can burst) Isotonic The concentration of solutes is the same inside and outside of the cell Water moves BOTH into and out of the cell (cell stays normal size)

53. Hypotonic Solution: Water moves into the cell – the cell swells & could burst

54. Hypertonic Solution: Water moves out of the cell – the cell shrinks

55. Isotonic Solution : Water moves into & out of the cell in equal amounts - the cell stays the same

56. Types of transport (con’t) Active Transport Moment of molecules against the concentration gradient (going in the opposite direction) –Requires energy from the cell Uses transport proteins that act as “pumps” to move molecules in the opposite direction of the concentration gradient Molecule to be carried Molecule being carried Energy

57. Active Transport 1.Molecular Transport: Sometimes the cell needs to move ions around against the concentration gradient. (Low to High concentration) The carrying of small ions (sodium, potassium, magnesium, calcium, etc) into or out of the cell against the concentration gradient is called molecular transport.

58. The molecules are carried across the membrane by another group of special proteins. EX) there is a protein to move potassium EX) there is a protein to move sodium EX) there is a protein to move calcium Since it is moving against the gradient, it requires energy.

59. 2. Endocytosis: (Cell eating) The process by which a cell takes material into the cell Types of endocytosis include: * phagocytosis: the cell surrounds and engulfs the material (brings in solid substances) pinocytosis: part of the cell pinches off forming a vacuole inside it (brings in liquid substances)

60. 3. Exocytosis (cell puking) The process by which a cell expels material from it. ** Molecular transport, Endocytosis, and Exocytosis all require energy.

61. Homeostasis Regulation of the internal environment so as to maintain a stable, constant condition; maintenance of the internal environment within tolerable limits; The Cell Membrane functions to maintain homeostasis within the cell. The Organelles function to help maintain homeostasis within the cell.

62. 2 Types of Organisms Unicellular – organisms made of only 1 cell and Multicellular – organisms made of many cells

63. Examples of Unicellular Organisms:

64. Examples of Multicellular Organisms: