Biology-Chap 1: Cell structure

What are the types of microscope

1. Light Microscope
2. Electron Microscope

What are the two types of electron microscope

1. Transmission Electron Microscope
2. Scanning electron microscope

Define Magnification

Number of times an image is enlarged, compared with the actual size of the object

Define Resolution

Ability to distinguish between two points clearly as separate

Unit of resolution

nm

What determines resolution

1. Range of electromagnetic radiation of different wavelengths
2. shorter wavelength used

What is the max resolution

-shortest distance between 2 separate points
- ½ wavelength used

What is the source of electromagnetic radiation

visible light

Wavelength of light microscope

400-700nm

Highest Magnification of light microscope

x1,500

Max resolution

200nm(low)

What is an advantage of light microscope

Live specimens can be viewed, image can be colored

What light microscope can only view

used for viewing structures that can be measured in micrometer

Source of Electron Microscope

Free electrons

Light microscope

has lower energy and longer wavelength than electrons

Electron Microscope

has high energy and very shorter wavele

Requirements for electron Microscope

Must be in a vacuum environment so electron can travel in straight lines

Highest magnification of electron microscope

x250,000

Max resolution of electron microscope

0.5nm(high)

What is a disadvantage of electron microscope

only dead material can be examined in vacuum images black and white

What appearance does (TEM) has

2D ap

What appearance does (SEM) has

3D appearance

List the differences between between a light and electron microscope

1.-visible light
-free electrons
2.-longer wavelength
-shorter wavelength
3.- x1,500
-x250,000
4.-200nm(low)
-0.5nm(high)