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Cells Structure and Function.ppt.pptx
- 1. Cells Structure and Function Usethis as a study tool for this Unit.
- 2. Section 1: Introductionto the Cell
- 3. Discovery of Cells ●The invention of the lens ● Robert Hooke (1665): observed a thin slice of cork (dead plant cells) with a microscope. He described what he observed as “little boxes” (cells).
- 4. Discovery of Cells ●Anton van Leeuwenhoek (1675): was the first person to observe living cells.
- 5. Microscopes ● Magnification: refersto the microscope’s power to increase an object’s apparent size ● Resolution: refers to the microscope’s power to show detail clearly
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- 8. Light Microscope Elodea -Aquatic Plant 40X 400X
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- 10. Transmission Electron Microscope(TEM) Herpes Virus Plant Root Cell
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- 13. Scanning Electron Microscope(SEM) Mosquito Head 200X 2000X
- 14. Scanning Electron Microscope(SEM) Fly Eye
- 15. Scanning Electron Microscope(SEM) Inside of Stomach Surface of Tongue Neuron
- 16. Scanning Electron Microscope(SEM) Pollen Yeast Red Blood Cell, Platelet, and White Blood Cell
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- 18. The Cell Theory ●Who developed the cell theory? – Matthias Schleiden (1838): concluded that all plants are composed of cells – Theodor Schwann (1839): concluded that all animals are composed of cells – Rudolph Virchow (1855): determined that cells come only from other cells
- 19. The Cell Theory ●What is the cell theory? 1. All living things are composed of one or more cells. 2. Cells are organisms’ basic units of structure and function. 3. Cells come only from existing cells.
- 20. Cell Diversity ● Size ●Shape ● Internal Organization
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- 22. Cell Diversity- Size 6inches long, 5 inches wide, 3 pounds Smallest Cells: Longest Cells: Ostrich Egg Biggest Cells:
- 23. Surface Area toVolume Ratio SA = 6 mm2 SA = 24 mm2 SA = 96 mm2 V = 1 mm3 V = 8 mm3 V = 64 mm3 SA/V = 6:1 SA/V = 3:1 SA/V = 1.5:1 V increases faster than SA SA = 6lw V = lwh
- 24. Cell Diversity- Shape ●Cells differ widely in shape. ● Most cells are roughly cuboidal or spherical.
- 25. Cell Diversity- InternalOrganization ● Nucleus: contains DNA which directs the activity of the cell ● Organelle: a cell component that performs specific functions in the cell ● Eukaryotes: cells that contain a nucleus and membrane-bound organelles ● Prokaryotes: cells that lack nuclei and membrane-bound organelles
- 26. Eukaryotes vs. Prokaryotes ●Eukaryotes (animals, plants, fungi, protists) and prokaryotes (bacteria) differ greatly in structure.
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- 29. Structural Organization ofEukaryotic and Prokaryotic Cells
- 30. Section 2: Partsthe Cell
- 31. The Parts ofthe Cell ● Each living cell carries out the tasks of taking food, transforming food into energy, getting rid of wastes, and reproducing. ● Most eukaryotic cells have three main components: – Cell Membrane – Cytoskeleton – Nucleus
- 32. Structure and Functionof Organelles ● The Structure and Function of the following organelles will be discussed: – Cell Membrane – Nucleus – Cell Wall – Cytoplasm – Cytoskeleton – Ribosomes – Endoplasmic Reticulum – Golgi Apparatus – Mitochondria – Lysosomes – Peroxisomes – Cilia and Flagella – Basal Bodies – Centrioles – Vacuoles – Plastids
- 33. Cell Membrane ● Structure:phospholipid bilayer with proteins that function as channels, markers, and receptors -also contains cholesterol which provides rigidity ● Function: selectively permeable boundary between the cell and the external environment
- 34. Nucleus ● Structure: thenucleus is a sphere that contains another sphere called a nucleolus ● Function: -storage center of cell’s DNA -manages cell functions
- 35. Cell Wall ● Structure:rigid wall made up of cellulose, proteins, and carbohydrates ● Function: boundary around the plant cell outside of the cell membrane that provides structure and support
- 36. Cytoplasm ● Structure: gelatin-likefluid that lies inside the cell membrane ● Function: -contains salts, minerals and organic molecules -surrounds the organelles
- 37. Cytoskeleton ● Structure: anetwork of thin, fibrous elements made up of microtubules (hollow tubes) and microfilaments (threads made out of actin) ● Function: -acts as a support system for organelles -maintains cell shape
- 38. Ribosomes ● Structure: consistof two subunits made of protein and RNA ● Function: location of protein synthesis
- 39. Endoplasmic Reticulum ● Structure:a system of membranous tubules and sacs ● Function: intercellular highway (a path along which molecules move from one part of the cell to another) ● Two types: – Rough Endoplasmic Reticulum – Smooth Endoplasmic Reticulum
- 40. Rough Endoplasmic Reticulum ●Rough Endoplasmic Reticulum (rER): prominent in cells that make large amounts of proteins to be exported from the cell or inserted into the cell membrane – Covered with ribosomes
- 41. Smooth Endoplasmic Reticulum ●Smooth Endoplasmic Reticulum (sER): involved in the synthesis of lipids and breakdown of toxic substances – Not covered with ribosomes
- 42. Golgi Apparatus ● Structure:stacked flat sacs ● Function: receives proteins from the rER and distributes them to other organelles or out of the cell (receiving, processing, packaging, and shipping)
- 43. Mitochondria ● Structure: folded membranewithin an outer membrane – The folds of the inner membrane are called cristae ● Function: -converts energy stored in food into usable energy for work – cellular respiration
- 44. Lysosomes ● Structure: spherical organellesthat contain hydrolytic enzymes within single membranes ● Function: breaks down food particles, invading objects, or worn out cell parts
- 45. Peroxisomes ● Structure: spherical organellesthat contain enzymes within single membranes ● Function: Degrade hydrogen peroxide, a toxic compound that can be produced during metabolism.
- 46. Cilia and Flagella ●Structure: hair-like organelles that extend from the surface of cells – When they are present in large numbers on a cell they are called cilia – When they are less numerous and longer they are called flagella – Both organelles are composed of nine pairs of microtubules arranged around a central pair. ● Function: cell motility
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- 48. Basal Bodies ● Themicrotubule assembly of a cilium or flagellum is anchored in the cell by a basal body. ● Structurally identical to a centriole
- 49. Centrioles ● Structure: composed ofnine sets of triplet microtubules arranged in a ring – Exist in pairs ● Function: centrioles play a major role in cell division (mitosis)
- 50. Vacuoles ● Structure: asac of fluid surrounded by a membrane – Very large in plants ● Function: used for temporary storage of wastes, nutrients, and water
- 51. Plastids ● There arethree types of plastids in plant cells: – Chloroplasts (discussed on next slide) – Chromoplasts: synthesize and store pigments – Leucoplasts: store food such as starches, proteins, and lipids Chromoplasts Red Pepper Flower Leucoplasts
- 52. Chloroplasts ● Structure: stacked sacs(thylakoids) that contain chlorophyll surrounded by a double membrane ● Function: photosynthesis (conversion of light energy to chemical energy stored in the bonds of glucose)
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- 55. Plant Cells vs.Animal Cells ● Animal cells are very similar to plant cells except for the following major differences: – Animal cells do not contain chloroplasts – Animal cells are not surrounded by cell walls – The vacuoles in plants are much larger than those of animals
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- 58. Microscope Pictures ofa Plant Cell and an Animal Cell Elodea Human Cheek Cells
- 59. The following isa list of tissues that have specialized functions and demonstrate corresponding specialization of subcellular structure. Match the tissue with the letter of the cell structures and organelles listed to the right that would be abundant in these cells. Tissues Cell Structures and Organelles 1. Enzyme (protein)-secreting A. plasma membrane cells of the pancreas B. mitochondria 2. Insect flight muscles C. Golgi apparatus D. chloroplast 3. Cells lining the respiratory E. ER passages F. cillia & flagella 4. White blood cells that engulf G. vacuole and destroy invading bacteria H. ribosome 5. Leaf cells in cacti I. lysosome J. peroxisomes ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓
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