Microscopes Chapter 15: Section 1

What does it do? There are a lot more objects in the world that we cannot see because they are so small It makes very tiny things, look big! It works similarly to a magnifying glass but not completely…

Magnification is not the only thing Magnification: How much an image is enlarged Microscopes enhances the RESOLUTION Resolution: Creates an enlarged view of an object without losing any of the details Without resolution, the magnification and thus the details would be fixed

The microscope we use today We use what is called a compound microscope or light microscope – Light passes through and around an object and then travels through two or more lenses – Called light or compound b/c it uses light and is made out of two or more lenses

Eyepiece Body Tube Revolving Nosepiece Arm Objective Lens Stage Stage Clips Coarse Focus Fine Focus Base Diaphragm Light

Not Picture Worthy Make sure that the stage is all the way lowered and the low powered lens is on Plug the microscope in and flip the switch.

Functions of the different parts Eyepiece: Part where you look through Revolving Nosepiece: Allows you to switch between different lenses Objective Lenses: Contains different powered lenses for greater viewing Stage: Where the glass slide sits while you look at the specimen Diaphragm: Allows different amounts of light come through

The Rest Stage Clips: Holds down the slide Light Source: Shoots the beam of light so object can be seen Base: Heavy part and keeps the microscope sturdy, first hand goes here Arm or Neck: Where your second hand goes Coarse Adjustment: Moves the stage up and down Fine Adjustment: Adjusts to focus of the object

History of the microscope Zacharias Janssen, put two lenses together inside a tube to create a very poor “microscope” in – This resulted in an image that we just saw that was magnified without resolution

Anton Van Leeuwenhoek 1600s Credited with the creation of the first microscope – One lens with a tiny hole – Specimen mounted on the sharp point – Position and focus controlled by screws – Was only 3-4 inches long

The other types Stereomicroscope or dissection scopes – Has two eye pieces instead of one to give more of a 3D view – Used to view items that are too think or too big for a compound microscope – Also for objects that light cannot pass through

We aren’t through with Electrons Electron Microscopes: To view items too small to be seen with a compound microscope. – Instead of light, this microscope uses magnetic fields to bend beams of electrons – It magnifies up to 1 million X! A common normal microscope only does ~430X

Two types of Electron Microscopes Transmission Electron Microscope (TEM) Scanning Electron Microscope (SEM) Used to see surfaces of an object Can study living things No vacuum or slicing Studies inside of a cell Sliced thin in vacuum Only dead cells and tissue

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