Microscopes

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Microscopes
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Objectives

• Relate advances in microscope technology to
  discoveries about cells and cell structure
• Compare the operation of a compound light
  microscope with that of an electron miroscope
• Identify the main ideas of the cell theory

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Before Microscopes

• Before microscopes people believed that diseases
  were caused by curses and supernatural spirits.

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MICROSCOPE

• Microscope ? tool used to look at small organisms
  (microorganisms)
• MICROSCOPE
• Micro small
• Scope to look at

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• MICROSCOPES ALLOW US TO SEE CELLS
• Cell ? basic unit of life

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Plant cell
Animal cell
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Kinds of Microscopes

• 3 Major kinds of microscopes
• Simple Light Microscope
• Compound Light Microscope
• Electron Microscope

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Simple Light Microscope

• Simple Light 1st type invented (1500s)
• 1 Lens
• Energy Source Light
• Low Magnification power

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Compound Light Microscope

• 2. Compound Light
• 2 Lenses
• Energy Source Sunlight or Electricity
• Up to about 1500 xs actual size

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Can you find the differences between simple and
compound?
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Magnification

• TOTAL MAGNIFIATION (lens) X (objective)
• lens 10X objective 4X (multiply)
• Total Magnification (10) X (4)
• 40 Xs actual size
• What is the total magnification of a microscope
  with an objective of 10x?

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Electron Microscopes

• Electron Microscopes
• Light Source beam of electrons
• Magnify up to 500,000 Xs actual size

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Electron Microscopes

• 2 kinds of electron microscopes
• SEM TEM

• Scanning Electron Microscope
• surface

• Transmission Electron Microscope
• inside

MAJOR DISADVANTAGE KILLS SPECIMEN
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Taken by a S.E.M.
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Can you guess what this is? It was taken by a
T.E.M.
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Carrying a Microscope

• CAREFULLY!!!!
• They are expenive!!
• One hand on ARM
• Other hand on BASE

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Microscope Label

• Turn to page 1070 in your book
• Label your microscope worksheet
• Write down vocab on back of paper

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Important Scientists
ONCE UPON A TIME in the mid 1600s

• Anton van Leeuwenhoek first microscope (single
  lens, used light to see object)
• Robert Hooke
• named cells
• looked at dead oak bark (cork), saw small
  chambers like rooms in a monastery
• Coined the term cell

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More Important Scientists

• Schleiden all plants made of cells

• Schwann all animals made of cells

Schwan sounds like swan (an animal)

• Brown some cells contain a prominent
  structure (aka nucleus)
• Virchow Browns structure (aka nucleus) is
  responsible for cell division

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Cell

• Cell basic units of living things
• atoms?make up?
• ?molecules?make up?
• ??organelles?make up?
• ???cells? make up ?
• ????tissues? make up?
• ????? organs ? make up?
• ??????organ systems ?make up?
• ???????Organisms (LIKE YOU!)

IS AN ORGANELLE A LIVING ORGANISM?
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The Summary of all these Ideas led to the Cell
Theory

• 1. All organisms are composed of one or more
  cells
• 2. The cell is the basic unit of living
  organisms
• 3. All cells come from preexisting cells

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Quick Project Cell Theory Foldable

• Make a tri-fold in a piece of paper
• Label each section with a PART of the cell
  theory
• Explain each part of the cell theory using a
  PICTURE
• Be sure to include any important scientists in
  your drawings where appropriate!
• You may use words to explain your picture, but
  the picture should do most of the talking, if
  you know what I mean

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Cells are made up of ORGANELLES

• Organelles specialized structures that have a
  specific function in the cell

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2 Types of Cells

• 2 kinds of Organelles and 2 kinds of CELLS

Prokaryotic Cells Eukaryotic Cells

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Eukaryotic Cells

• Membrane-bound organelles
• Have nucleus
• Most come from multicellular (plants/animals)
• Can be unicellular (some protists ameba
  paramecium)
• Larger

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Prokaryotic

• No nucleus
• No membrane-bound organelles
• Contain Ribosomes
• Single celled organisms (usually)
• Smaller (usually)
• Round DNA/RNA called Plasmids
• Example bacteria

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Plant cell
Plant cell vs. Animal cell
Animal cell
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Plant cell
What differences do you see?
Animal cell
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Plants vs. Animal

• Plants contain
• Cell wall
• Chloroplast
• Large vacuoles
• Some animal cells contain vacuoles smaller
  more numerous
• Why do plants need LARGE vacuoles?

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Plants vs. Animal

• Animal cells contain
• NO cell wall (only membrane)
• Small vacuoles
• Why would an animal only need SMALL vacuoles?

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Organelle Animal Cell Plant Cell
Shape Round (irregular shape) Rectangular (fixed shape)
Golgi apparatus Present Present
Cilia Present It is very Rare
Nucleus Present Present
Mitochondria Present Present
Cytoplasm Present Present
Chloroplast Animal cells don't have chloroplasts Plant cells have chloroplasts because they make their own food
Cell wall None Yes
Plasma Membrane only cell membrane cell wall and a cell membrane
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Organelle Animal Cell Plant Cell
Flagella May be found in some cells May be found in some cells
Lysosomes Lysosomes occur in cytoplasm. Lysosomes usually not evident.
Ribosomes Present Present
Endoplasmic Reticulum (Smooth and Rough) Present Present
Vacuole One or more small vacuoles (much smaller than plant cells). One, large central vacuole taking up 90 of cell volume.
Centrioles Present in all animal cells Only present in lower plant forms.
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