1 / 39

Cells

Cells. The Universal Subunits of Life. Cellular Structure. all life is cellular Cell Theory Cells are the fundamental units of life. All organisms are composed of cells. All cells come from preexisting cells.

lis
Download Presentation

Cells

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cells The Universal Subunits of Life

  2. Cellular Structure • all life is cellular • Cell Theory • Cells are the fundamental units of life. • All organisms are composed of cells. • All cells come from preexisting cells. • each cell possesses the different molecules necessary for sustaining life & specializations (≥10,000)

  3. Cellular Structure • all life is cellular • all cells belong to one of two structural categories • prokaryotic cells - relatively simple • eukaryotic cells - more complex

  4. Cellular Structure • prokaryotic cells • cytoplasm surrounded by plasma membrane • cytosol + insoluble particles • DNA in nucleoid • no membrane-bound organelles • cell wall (most) • complex, highly regulated metabolism • distinguished by many non-universal characteristics

  5. some common prokaryotic charactersFigure 4.5

  6. Bacterial FlagellumFigure 4.6

  7. relative sizes of organisms and their constituentsFigure 4.2

  8. Cellular Structure • eukaryotic cells • larger, but still small

  9. cell size is limited by surface area/volume ratioFigure 4.3

  10. Cellular Structure • eukaryotic cells • larger, but still small • plasma membrane • cytoskeleton • membrane-bound organelles

  11. Animal & Plant CellsFigure 4.7

  12. cell fractionationby centrifugationpermits biochemical analysisthat supplements microscopic observationsFigure 4.8

  13. Organelle Functions • information processing organelles • nucleus • an envelope of two membranes • perforated by pores • the outer membrane is linked to the ER • contains • nucleoplasm • chromatin • nucleoli

  14. nuclear structuresFigure 4.9

  15. Organelle Functions • information processing organelles • nucleus • chloroplasts (cp) & mitochondria (mt) • contain DNA like prokaryotic cells • express some essential proteins

  16. Organelle Functions • information processing organelles • nucleus • chloroplasts (cp) & mitochondria (mt) • ribosomes • complex RNA-protein bodies • translate instructions into polypeptides • in cytoplasm, on ER, in cp & mt

  17. Organelle Functions • energy processing organelles • mitochondria • major site of oxidative energy production • two membranes surround aqueous matrix that contains energy-processing enzymes • the highly folded inner membrane (cristae) bears energy-processing enzymes

  18. MitochondrionFigure 4.14

  19. chromoplasts leucoplasts Figure 4.17

  20. Organelle Functions • energy processing organelles • mitochondria • plastids • a two-membrane envelope • store/produce energy or display colors • chloroplasts • thylakoid membranes are suspended in the stroma • each contains enzymes of energy production

  21. ChloroplastFigure 4.15

  22. endosymbiotic origin of cp & mtFigure 4.18

  23. Organelle Functions • the endomembrane system • a system of interacting membranes located throughout the cell • endoplasmic reticulum (ER) • continuous with the nuclear outer membrane • the membrane encloses the lumen • translates & processes proteins headed for organelles, membranes, outside • RER (rough), SER (smooth)

  24. rough & smooth endoplasmic reticulum (RER, SER)Figure 4.11

  25. Organelle Functions • endomembrane system • interacting membrane organelles throughout the cell • endoplasmic reticulum (ER) • Golgi apparatus • flattened sacks (cisternae) + vesicle shuttles • proteins travel from ER to cis face to trans face

  26. endomembrane system functionFigure 4.12

  27. Organelle Functions • endomembrane system • interacting membrane organelles throughout the cell • endoplasmic reticulum (ER) • Golgi apparatus • lysosome • vesicle with digestive enzymes • fuses with phagosome

  28. lysosome functionFigure 4.13

  29. Organelle Functions • other organelles • peroxisome • detoxifies peroxides

  30. Figure 4.19

  31. Organelle Functions • other organelles • peroxisome • detoxifies peroxides • glyoxysome (plants only) • converts lipids to carbohydrates • vacuole (plants) • maintains turgor pressure • stores reserves, wastes • visual attractant (anthocyanins)

  32. Figure 4.20

  33. microfilaments stabilize cell shapeFigure 4.22

  34. 9+2 arrangement of microtubules in ciliumFigure 4.23

  35. mechanism of microtubular movementFigure 4.24

  36. Extracellular Structures • plant, fungi cell wall • prevents cell from bursting

  37. Plant Cell WallFigure 4.25

  38. Extracellular Structures • plant, fungi cell wall • animal extracellular matrix • secreted by adjacent cells • differs from tissue to tissue

  39. An extracellular matrixFigure 4.26

More Related