2. 7-1: Life is cellular 7-2: Cell structures 7-3: Movement through the membrane 7-4: The diversity of cellular life

5. The Cell Theory  All living things are made up of cells.  All cells come from pre-existing cells.  Cells are the basic unit and structure of all living things. Contributors to the Cell Theory  Hooke – Named cells and observed cork  Leewenhoek – Observed living cells  Schliden – cell theory plants  Schwann – cell theory animals  Virchow – cell theory reproduction

7. Basic Cell Structures:  Cell membrane – the thin barrier around all cells  Cytoplasm – the material inside the cell membrane  Ribosomes – small structures that manufacture proteins

8. Prokaryotes (bacteria)  Small  Simple  Contain DNA but no nucleus  Examples include:  Escherichia coli  Staphylococcus aureus Eukaroytes  Large (in comparison)  Complex with many organelles – specialized structures that perform important cellular functions.  Contain a nucleus that contains DNA  Examples include:  Plants  Animals  Fungi Biologists divide cells into two basic categories: Eukaryotic cells or Prokaryotic Cells

13. Structure (What it’s made of) :  Thick, jelly-like fluid Function (What it does) :  Holds all organelles  Location of many cellular chemical reactions

14. Structure:  Nuclear envelope that contains pores or holes  Dark center called a nucleolus which manufactures ribosomes and contains RNA  Packaged DNA called Chromatin Function:  Controls all the cell’s activities  Protects the cell’s information  Brain of the cell

15. Structure:  Microtubules – hollow tubes of protein  Microfilaments – thin narrow fibers Function:  Maintains cell’s shape  Highway system for organelles

16. Structure:  Part of cytoskeleton  Only in animal cells  Packs of microtubules Function:  Helps cells to divide

17. Structure:  Part of cytoskeleton  Microtubules Function:  Movement

18. Structure:  Tiny  No outer membrane  Found in both eukaryotic and prokaryotic cells Function:  Make proteins!!!

19. Structure:  Network of membrane tubes  Rough E.R. is covered with ribosomes  Smooth E.R. has no ribosomes Function:  Transports materials within the cell  Modify proteins  Filters out toxins

20. Structure:  Stacks of membranes  Looks like pancakes Function:  Modify and package cellular materials  “Post office”

21. Structure:  Membrane filled with digestive enzymes  Only found in animal cells Function:  Trash compactor/ Stomach of cell  Helps fight infection

22. Structure:  Membrane bag Function:  Stores food, water and waste  Help give plant cells rigidity

23. Structure:  Peanut shaped  Folded layers of membrane inside called, cristae Function:  Powerhouse  Cell Respiration (makes energy)

24. Structure:  Green  Contains stacks of membranes  Only in plants Function:  Photosynthesis  A type of plastid (a vacuole that contains pigment)

26. Structure:  Phospholipid (fats) bilayer  Proteins  Carbohydrates Function:  Creates a boundary around the cell  Regulates what goes in and out of the cell

27. Structure:  Only in plant cells and bacteria cells  Contains cellulose Function:  Rigidity  Protection

28. OrganelleStructureFunction NucleusDNA (chromatin) Nucleolus Brain Cell MembranePhospholipid bilayerRegulates what goes in and out Cell WallCelluloseProtection/rigidity CytoplasmJellylikeHolds organelles cellular reactions CytoskeletonMicrotubules microfilaments Supports the cell moves organelles RibosomesTiny round structures Found in ER and cytoplasm Make proteins ERNetwork of tubes Rough or smooth Transports proteins gets rid of toxins

29. OrganelleStructureFunction Golgi Apparatus Stacks of membranes (pancakes) Modify and package proteins and other cellular materials (post office) VacuolesSaclike structuresStores food, water, and waste MitochondriaPeanut shaped Folded layers inside (Cristae) Powerhouse (mighty!) ChloroplastOnly in plants Green bundles Holds pigments and carries out photosynthesis LysosomeSac of digestive enzymes Disposes of wastes (trashcan) CentriolesOnly in animal cellsHelps cells divide Cillia/FlagellaOnly in animal cells Hairlike projections Movement of the cell

30. Centrioles Nucleolus Nucleus Nuclear envelope Rough endoplasmic reticulum Golgi apparatus Smooth endoplasmic reticulum Mitochondrian Cell Membrane Ribosome (free) Ribosome (attached) Figure 7-5 Animal Cell

31. Nuclear envelope Ribosome (attached) Ribosome (free) Smooth endoplasmic reticulum Nucleus Rough endoplasmic reticulum Nucleolus Golgi apparatus Mitochondrian Cell wall Cell Membrane Chloroplast Vacuole Figure 7-5 Plant Cell

32. Lysosomes Centrioles Small Vacuole

35. Lipid bilayer:  phospholipids  Hydrophilic head  Hydrophobic tail Proteins:  On top/bottom  Through  Act as passageway Carbohydrates:  Cell Recognition

36. Fluid mosaic model: the cell membrane is like a liquid  Phospholipids are constantly changing positions Membrane is a mix/ mosaic of different chemicals Membrane is selectively permeable - some things move through and some things do not

37. Passive transport (high to low)  No energy needed. Active transport (low to high)  Needs energy.

38. Diffusion is a type of Passive transport Molecules move down a concentration gradient (High to Low) Diffuse to reach equilibrium : concentration of molecules is the same throughout the space Equilibrium

40. Osmosis is a type of passive transport  Osmosis is the movement of water from a high concentration to a low concentration Recall:  Solute is the substance being dissolved  Solvent is the substance doing the dissolving

41. ISOTONIC Solution:  Amount of water in and out of cell is equal  Result: Even flow of water into and out of cell.  EX: Blood HYPOTONIC Solution:  More water outside than inside the cell.  Result: Water rushes in and cell bursts (cytolysis) or becomes firm (turgor pressure) HYPERTONIC Solution:  Less water outside than inside the cell.  Result: Cell shrinks (plasmolysis) Flash Movie Animal Cells Only Plant Cells Only

43. Hypotonic Isotonic Hypertonic

44. Upper Left: ISOTONIC Upper Right: HYPERTONIC Lower Left: HYPOTONIC

45. How do you catch a unique rabbit?

46. Unique up on it!!!

47. Which direction are the molecules moving? What is the net movement of molecules? What direction will the molecules be moving at equilibrium? What is the net movement of molecules at equilibrium? Water 98% NaCl 2 % NaCl 6% Water 94%

48. Animal cells  bursting of cells from a hypotonic environment = cytolysis (hypotonic)  Some cells can adapt to hypotonic environments with an organelle called a contractile vacuole – it fills with water and then squeezes it out of the cell. Plant cells  The rigid cell wall prevents bursting  Turgor pressure is pressure that water exerts against the cell wall (hypotonic)  Plants without water wilt and die this is called plasmolysis (hypertonic)

49. Contractile Vacuole

50. Facilitated diffusion is a type of passive transport Facilitated diffusion is the movement of large molecules across a membrane Carrier proteins – facilitate (help) movement  Ex. Glucose moves through a carrier protein

51. Diffusion – High to low Facilitated Diffusion – High to low with the help of a protein carrier * * * * * * * * * * * * **

52. Molecule to be carried Low Concentration Cell Membrane High Concentration Molecule being carried Low Concentration Cell Membrane High Concentration Energy Review Movie Active Transport movement of molecules from low to high concentration  Energy is needed to do this! Types:  Vesicle Transport:  Endocytosis – cell eating/drinking  Exocytosis – cell spitting material out  Protein Pumps – use energy (ATP) to pump materials from low to high concentrations

53. Endocytosis  Formation of a vesicle  Pinocytosis : cell drinking  Phagocytosis : cell eating  Phagocytes : eat and kill bacteria in our body Exocytosis  Vesicles fuse with the cell membrane to release contents into external environment

54. Cells in multicellular organisms are specialized, this mean each cell type has a specific job to keep the whole organism running.  For example:  blood cells carry oxygen to all the cells of the body.  Nerve cells have the ability to send electrical impulses throughout the organism. The levels of organization in a multicellular organism are:  Individual cells (heart cell)  Tissues (cardiac tissue)  Organs (heart)  Organ Systems (cardiovascular system)

55. Describe the structure of a membrane. Define the fluid mosaic model. Differentiate between passive and active transport. List and define the types of passive transport. Explain the effects of osmosis in different solutions (ex. iso, hypo, hyper.) Identify cells in isotonic, hypertonic, and hypotonic solutions. Explain how some cells/organisms respond to different osmotic environments. List and define the types of active transport.