1. Microscopes
Section 4.2

2. Learning Objectives
Explain the relationship between a microscopes magnification and resolution
Identify the two main types of microscopes and what each one is used for
Identify two different types of electron microscopes

3. Unit Conversion Chart (Don’t Have to Copy This!)

4. Cells Are Microscopic Most cells are 10-20 µm (micrometers)
Can’t see with just your eyes
Microscopes are used to observe cells
Magnification = ratio of the size of the image seen with the microscope to the actual size of the object
Resolution = ability to distinguish fine detail in an image
Depends on the quality of the lenses & wavelength of the light used

5. 2 Main Types of Microscopes
Light Microscope
Electron Microscope

6. Light Microscope
Curved glass lenses bend and focus light that passes through and object & creates a magnified image
Also called a compound microscope because it uses multiple lenses
Can only magnify objects about 1,000 times
Has a resolution of about 2𝜇m
Used to see living organisms

7. Parts of a Light Microscope (Put on Diagram Page!)

8. Parts of a Light Microscope (Put on Diagram Page!)
Eyepiece
Arm
Objectives
Stage
Course Adjustment
Fine Adjustment
Lamp
Base

9. Electron Microscope
Use magnetic fields to focus a beam of electrons onto an object
Images are black & white, but can be artificially colored
Resolution of 2 nm
Can’t see living things with it
The object is placed in a vacuum

10. 2 Types of Electron Microscopes
Transmission electron microscope (TEM)
Used to study the internal details of a cell
Scanning electron microscope (SEM)
Used to study surface structure of cells
Makes a 3-D looking image