Cell Theory

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Cell Theory Cellular Organelles

• Biology A

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Student learning Goals

• Students will...
• Explain how cells are the basic unit of structure
  and life for all living things.  
• Identify the parts of plant and animal cells.
• Compare prokaryotic and eukaryotic cells.

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Cell History

• 1665 First cells seen and named "cells" by
  Robert Hooke
• 1674 First protists seen swimming in a drop of
  water by Anton van Leeuwenhoek
• 1838 Matthias Schleiden said all plants were
  made of cells.

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Cell History- 2

• 1839 Theodor Schwann said all animals were made
  of cells.
• 1855 Rudolf Virchow said all cells come from
  existing cells.

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Cell Theory (1838-1855)

• All living things are made of cells.
• Cells are the basic unit of structure and
  function in living things.
• New cells come from existing cells.

Robert Hookes 1665 drawing of the first cells
seen under the microscope. (Cork cells)
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Two Kinds of Cells

• Eukaryotic

• Prokaryotic

• More complex cells
• Well defined organelles (cell parts)
• Cell wall (in some cells) and a complex, well
  defined membrane.
• Highly organized 
• Protists, high level plants, and animals

• More simple cells
• Few to no recognizable organelles (cell parts)
• Cell wall and a simple membrane
• Appears more disorganized
• Bacteria cells

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Parts of a Cell

• Cellular Organelles

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Eukaryotic Cells
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Organelle Cell Membrane

• Form thin double layer of lipids and proteins
  surrounding the cell
• Function Controls what gets in and out of the
  cell.Protects cell contents from environment.
• Found in all cells

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Organelle Cell WALL

• Form rigid covering surrounding cell membrane
• made of cellulose in plants, and algae (protists)
  
• made of chitin in fungi
• made of peptidoglycan in bacteria
• Function ProtectionGives shape
• Found in Plants, Bacteria, Fungi, Some Protists

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Additional layers in Prokaryotes

• Prokaryotes add additional layers of protection
  between their cytoplasm and their environment.
• They can have
• A second cell membrane
• A capsule outside the cell wall

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Organelle Cytosol

• Form Fluid soup inside the cell, surrounding
  the organelles
• Cytoplasm cytosol organelles
• Function cushions and protects organelles
• Found in all cells

(except the nucleus)
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Human cheek (squamous epithelial) cells

• What is the most obvious organelle?

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Organelle Nucleus

• Form large, round organelle w/
• Nuclear membrane
• Nuclear pores
• Chromatin (chromosomes) (DNA)
• Nucleolus (makes ribosomes)
• Function Directs and controls cellular
  activities
• Holds the DNA
• Found in Eukaryotic cells

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The Nucleoid

• Prokaryotes have a Nucleoid region which is the
  chromatin / DNA

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Organelle Mitochondrion

• Form bean-shaped, with inner and outer membranes
• Function Supply energy to the cell by breaking
  down sugar molecules by cellular respiration
• Found in All Eukaryotic cells. plural
  mitochondria

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Organelle Chloroplast

• Form bean-shaped, with pigment chlorophyll
• Function photosynthesis
• Found in Plants and protists

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Organelle thylakoid

• Some prokaryotes can also photosynthesize, using
  a membrane called a thylakoid.

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Organelle Endoplasmic Reticulum

• Form a folded membrane stretching between the
  nuclear membrane and the cell membrane
• smooth ER w/o ribosomes
• rough ER w/ ribosomes
• Function assembles components of cell membrane,
  modifies proteins, and synthesis of lipids
• Found in all Eukaryotic cells.

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Organelle Ribosome

• Form little grainy bumps in the cytoplasm and on
  the surface of the rough E.R.
• Function Makes protein molecules using
  instructions from DNA
• Found in All cells.

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Organelle Golgi Apparatus

• Form folded membranes with bubbles pinching off
  the sides
• Function Packages and ships molecules
• Found in Eukaryotic cells.

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Organelle Vacuole

• Form membrane-bound bubble in cytoplasm, large
  and central in plant cells, small and numerous in
  animal cells
• Function stores molecules, in plants it also
  provides support through turgor pressure and
  stores waste products
• Found in Eukaryotic cells

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Organelle Lysosome

• Form like a vacuole, a membrane-bound bubble
• Function Digestion breaks down carbohydrate,
  protein and lipid molecules into smaller
  molecules
• Found in Animal cells

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Organelle Microtubules

• Form hollow tubular rods
• Function structure and support (cytoskeleton)
  tracks to move cellular organelles around the
  cell
• Found in Eukaryotic cells.

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Organelle Centrioles

• Form paired bundles of microtubules located near
  the nucleus (in animal cells only)
• Function cell division
• Found in Animal cells

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Organelle Flagellum

• Form a whip-like tail composed of bundled
  microtubules
• Function propels cell through its environment
• Found in Bacteria, protists, animal sperm cells
• plural flagella

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Organelle Cilia

• Form tiny, hair-like extensions covering the
  surface of a cell.
• Function Movement, increase of surface area,
  move food towards "mouth"
• Found in Bacteria, Protists, animal epithelial
  cells

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Organelle Pilus

• Form extension of cell membrane that look like
  little hairs
• Function Helps prokaryotic cells stick to
  surfaces.
• There is a second type used in conjugation
  (sexual reproduction in bacteria)
• Found in Prokaryotic cells
• Plural pili

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Cell Models Review

• Go to the Cells Alive! Web sitehttp//www.cellsa
  live.com/cells/cell_model.htm

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Organelles Test yourself!
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Organelles Test yourself!
What kind of cell is this?
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Organelles Test yourself!
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Organelles Test yourself!
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Organelles Test yourself!