Module 1/ Cell size and Microscopy

Question 1

Light Microscope

Answer 1

Visible light is passed through a specimen and then through glass lenses. Lenses refract light to magnify image up to 1000 times the size. The resolution limit is ~ 200nm so most subcellular organelles are too small to be seen

Question 2

Transmission Electron Microscope

Answer 2

You can see the internal structure. The electrons block large structure. When you have a space with light organelles, it will be lighter. Focus beam of electrons through a thin specimen, to study internal structures. Resolution limit ~50 pm

Question 3

Scanning Electron Microscope

Answer 3

You can see the 3D shape of the cell organisms. The specimens is coated with gold, which emits emits electrons. You have an electron gun or beam, the electron beam then scans the gold specimens. That’s why you see the just the surface.

Question 4

Fluorescence Microscope

Answer 4

a type of light microscopy where specific molecules are visualized with fluorescently-labelled dyes or antibodies which allows for sub-cellular localization to be determined.

Question 5

What is the formula of cell volume and surface area?

Answer 5

volume:4/3 pie r^3
surface area:4pier^2