Microscopy Flashcards

All 6 cards in this deck

What is the formula for magnification?

magnification = size of image $\div$ size of real object

What are the steps to find the real size of an object from a microscope image?
e.g. an image 50 mm long at magnification $\times 100$

1. Start from magnification = image size $\div$ real size
2. Rearrange: real size = image size $\div$ magnification
3. Divide: $50 \div 100 = 0.5$ mm

How does an electron microscope compare with a light microscope?

It has much higher magnification and resolving power, so cells can be studied in much finer detail and more sub-cellular structures can be seen.

What do the prefixes centi, milli, micro and nano mean?

$10^{-2}$, $10^{-3}$, $10^{-6}$ and $10^{-9}$ of the unit.
e.g. 1 nm $= 1 \times 10^{-9}$ m

How do you convert a length in millimetres into micrometres?
e.g. $0.05$ mm

1. 1 mm $= 1000\ \mu$m
2. Multiply by 1000: $0.05 \times 1000 = 50\ \mu$m

True or false? Ribosomes can be seen using a light microscope.

False. They are too small — an electron microscope is needed because of its higher resolving power.