Cell Organelles!

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Cell Organelles!
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First, what are cells?

• Smallest living unit.
• Most are microscopic.

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Discovery of cells

• Robert Hooke (mid-1600s)
• Observed sliver of cork
• Saw row of empty boxes
• Coined the term cell
• (1839)Theodor Schwann Matthias Schleiden
• all living things are made of cells
• (50 yrs. later) Rudolf Virchow
• all cells come from cells (CELL THEORY)

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Cell Theory

• All living things are made of cells
• Smallest living unit of structure and function of
  all organisms is the cell
• All cells arise from preexisting cells
• (this principle discarded the idea of spontaneous
  generation)

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All cells have

• A surrounding membrane
• Protoplasm cell contents in thick fluid
• Organelles structures for cell function
• Control center with DNA

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Types of cells

• Prokaryotic cells
• Do not have a membrane bound nucleus
• Nucleoid region of DNA concentration
• Organelles not bound by membrane

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And..

• Eukaryotic cells
• Has a true nucleus bound by membrane
• Include fungi, protists, plant, and animal cells
• Possess many organelles

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Organelles

• Specialized subunits of cells that have a
  particular function
• Prokaryotes have a few (e.g., ribosomes)
• Eukaryotes have many, usually surrounded by a
  membrane
• This where we get the term Membrane-bound
  organelles

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Cell Membrane

• Also called plasma membrane
• Protects and supports the cell
• Controls what enters and leaves the cell
• It is a lipid bilayer (what does this mean??)
• Found in all types of cells prokaryotes and
  eukaryotes!

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Cell Wall

• Found in eukaryotic plant and protist cells also
  in prokaryotes
• Main function is protection, rigidity, and
  support
• Outside of cell membrane
• Made of cellulose (a carb!)
• Allows water and dissolved substances to pass
  through.

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The Nucleus

• Controls most activities in the cell
• Usually one per cell
• Contains DNA the coded instructions for making
  proteins and other molecules for the cell
• The nuclear envelope has nuclear pores, where
  things can enter or leave

See?
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Nucleolus

• Small, dense region in the middle of the nucleus
• This is where ribosomes are formed.

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Cytoplasm

• Clear fluid within cell that contains all
  organelles
• Moves materials throughout the cell

Its the light blue/gray stuff in this picture
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Ribosomes

• Makes proteins in the cell
• May be free in cytoplasm or attached to ER
• Proteins are vital to life all cells must
  produce them!!!

In prokaryotes and eukaryotes
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Golgi Apparatus (Bodies)

• Stacks of membranes used for storing, modifying,
  or packaging (the cells packaging plant!)
• Packaged chemicals can be stored inside the cell
  or move outside the cell
• Cells that make saliva or mucus have many Golgi
  bodies

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Endoplasmic Reticulum

• Series of folded membranes that form sacs or
  tubes
• Two types smooth and rough

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Smooth ER vs. Rough ER

• Rough ER
• Ribosomes make it look rough or bumpy
• Ribosomes synthesize (make) proteins, so the
  Rough ER is where this happens!

• Smooth ER
• Smooth - no ribosomes!
• Synthesizes (makes) lipids
• Detoxifies drugs

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Lysosomes

• Made by the Golgi Apparatus
• Full of digestive enzymes to digest unwanted
  particles
• Help white blood cells to destroy bacteria
• Clean-up crew!

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censored!!!
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Peroxisomes

• Filled with enzymes to digest toxic substances
• Numerous in the liver
• Do not form at Golgi Body

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Vacuoles

• Store food, water, or waste materials
• In plant cells, they are very large!

Vacuoles and lysosomes working together! Amazing!
Astounding!
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Chloroplasts

• Found in eukaryotic plant cells some protist
  cells
• Capture light energy and convert it into chemical
  energy during photosynthesis

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Mitochondria

• Energy producers the powerhouse of the cell!
• Convert chemical energy into useable energy
• Found in animal and plant cells

• Many mitochondria in muscle cells why??
• Contain DNA from ovum so all your mitochondria
  are from your mom! (Thanks, Mom)

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Cytoskeleton

• Overlapping network of filaments and fibers that
  support the cell and help it maintain its shape
• Can also help cells move
• Microfilaments and microtubules

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Centrioles

• Help to organize the cell during cell division
• They migrate to either side of the cell and help
  to pull it apart
• Only found in animal cells!

Centrioles are made of microtubules
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Flagellum

• Extension of the cytoskeleton- Allows movement,
  main source of transportation for cells
• Only some animals and some prokaryotes have these

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Cilia/Pili

• Extension of the cytoskeleton- Allows things to
  move around the cell. Propels mucus in your
  throat, helps with hearing in your ears, and
  helps move food particles in your stomach.
• Only some animal cells and some prokaryotes

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Some organelles have their own DNA.

• Two organelles have their own DNA mitochondria
  and chloroplasts.
• Among multicellular animals, nearly all of the
  mtDNA in a fertilized egg is inherited from only
  the mother.
• One mechanism for this is simple dilution an egg
  contains 100,000 to 1,000,000 mitochondria,
  whereas a sperm contains only 10 to 100.

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Endosymbiotic Theory

• Mitochondria and chloroplasts descended from
  ancient prokaryotes that developed symbiotic
  relationships with ancient cells.

• In other words mitochondria and chloroplasts are
  former prokaryotes that now live inside
  eukaryotes!

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More Historic Figures

• 1600s
• Robert Hooke cork cells
• Anton van Leeuwenhoek animalcules
• 1800s
• Matthias Schleiden Father of Cell Theory
• 1900s
• Janet Plowe cell membrane is an actual structure
• George Langford from NC! Breakthroughs in
  understanding the cytoskeleton

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The End
I
Cells!