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CELLS

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Title: CELLS


1
CELLS
  • The Fundamental Units of Life

2
Cell Theory
  • All organisms are composed of 1 or more cells.
  • The cell is the basic living unit, providing
    organization for all organisms.
  • All cells arise from preexisting cells.

3
Cells Are Small
  • Most are too small to be seen with the unaided
    eyeso Microscopes are used.
  • A Light Microscope uses visible light shone
    through glass lenses.
  • A thin section of specimen is required.
  • van Leeuwenhoek

4
Principles of Microscopy
  • LIGHT
  • REFRACTION
  • MAGNIFICATION
  • RESOLUTION

5
RESOLUTION
6
Cells!
7
CELLS
  • Eukaryotic Cells (animals, plants, fungi,
    protists)
  • Complex relatively large.
  • Membrane-bound nucleus organelles.
  • 80-S Ribosomes.
  • Prokaryotic Cells (archaea, bacteria)
  • Simple relatively small.
  • NO Membrane-bound nucleus organelles.
  • 70-S Ribosomes.

8
CELLS
  • PROKARYOTIC EUKARYOTIC

9
EUKARYOTIC CELLS
Organelles little organs (not really)
Membrane-bound
10
ORGANELLES
  • Nucleus
  • Isolates the DNA provides access to its
    hereditary information.
  • The control center of the cell (Transcription).

11
Nucleus
  • Nuclear Envelope (a double membrane)
  • with Pores.
  • Nucleolus
  • rRNA
  • Proteins
  • Ribosomes
  • Nucleoplasm
  • with Chromatin/Chromosomes.

12
Ribosomes
  • Not true organelles, more structures.
  • Protein factories.
  • 2 sub-units.
  • Free (in cytoplasm), more for intracellular
    activities.
  • Bound (on E.R.), often for extracellular
    activities (secretion) packaging within certain
    organelles.

13
Endomembrane System
  • Synthesis of Proteins their transport.
  • Packaging of Proteins for transport out of the
    cell (secretion) or to other areas of the cell.
  • Modification of Proteins.
  • Transport of lipids, lipoproteins, glycoproteins,
    etc.

14
Endomembrane System
  • Endoplasmic Reticulum (E.R.)
  • Rough E.R.
  • Smooth E.R.
  • Golgi Apparatus
  • Vesicles
  • Lysosomes
  • (also, nuclear envelope, vacuoles, and plasma
    membrane)

15
Endoplasmic Reticulum
  • Network of interconnected membranes (continuous
    with the nuclear envelope).
  • Flattened or tubular.

16
Rough E.R.
  • The site of protein manufacture initial
    modification, particularly of secretory proteins.
  • Formation (budding) of Transport Vesicles.

17
Smooth E.R.
  • Modification of proteins formation of Lipids.
  • Lipid-derived hormones (steroids) are
    synthesized, including sex hormones
    (testosterone, etc.) in certain glands.
  • Detoxification (drugs, alcohol, caffeine, etc. )
    in liver cells.

18
Golgi Apparatus
  • Major modification, sorting, shipping of
    ER-produced items (esp. for secretion).
  • Addition of non-protein portions to protein
    molecules.

19
Lysosomes
  • Vesicles carrying digestive enzymes hydrolytic
    (proteolytic) enzymes.
  • Animal Cells.
  • Digestion of food brought in by phagocytosis.

20
Lysosomes
  • Digestion and recycling of old damaged
    organelles within the cell Autophagy.

21
Endomembrane System
22
Vacuoles
  • Large vesicles with particular functions.
  • Food Vacuoles.
  • Contractile Vacuoles.
  • Central Vacuole w/ tonoplast in Plant Cells.
  • Storage.
  • Dissolved Solutes.
  • Dumping Ground.
  • Protection.
  • Shape.

23
Mitochondrion
  • Site of cellular respiration energy production.
  • Carbohydrates ATP
  • Not part of endomembrane system.
  • Have their own DNA, RNA, Proteins, and Ribosomes
    (70-S).
  • Grow and reproduce independently.
  • Animals, Plants, Fungi, Protists.

24
Mitochondrion
  • Surrounded by a double membrane an envelope.

Outer Membrane Inner membrane (Cristae) Matrix
25
Chloroplast
  • Site of Photosynthesis acquisition of chemical
    energy from sunlight.
  • Sunlight CO2 Carbohydrates
  • A plastid (not part of endomembrane system).
  • Have their own DNA, RNA, Proteins, and Ribosomes
    (70-S).
  • Grow and reproduce independently.
  • Plants, Protists.

26
Chloroplast
  • Surrounded by a double membrane an envelope.

Inner Membrane (Grana composed of stacked
Thylakoids)
Outer Membrane
Stroma
27
Cytoskeleton
  • Fiber-like structures that lend organization.
  • Support (providing a scaffolding onto which
    organelles vesicles can be organized).
  • Shape (maintain particular shape depending on the
    cells location and/or function).
  • Transport of materials around or out of the cell.
  • Motility of the whole cell from one location to
    another.

28
Cytoskeleton
  • Microtubules Microfilaments Intermediate
    Filaments

Keratin Subunits
Tubulin
Actin
Keratin
29
Cytoskeleton
  • Permanent
  • Flagella
  • Cilia
  • Muscle Contraction
  • Scaffolding Shape Maintenance

30
Cytoskeleton
  • Transient
  • Spindle Fibers
  • Transport filaments

31
Cell Wall
  • OUTSIDE the Cell Membrane (technically, outside
    the cell!)
  • Various proteins glycoproteins in Prokaryotes.
  • Cellulose in Plants.
  • Chitin in Fungi.

32
Eukaryotic Cell
33
Endosymbiont Theory
34
Onion Cells
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