Bio 219 Lab Quiz WVU

Beer-Lambert law

• A = εlc

• Measures absorbance based on concentration

• A: Absorbance

• ε: Molar absorptivity

• c: Concentration

• l: Path length

Michaelis Menten equation

• v = Vmax[s]/K_m + [s]

• [s]: Concentration of the substrate

• K_m: (1/2)(Vmax)

How do PCR reactions work and what are its reagents?

1. DNA is denatured by heat

2. DNA is copied from a primer

3. Reannealing occurs when the temperature is lowered again

• You need template DNA, DNA polymerase, forward primer, reverse primer, and buffer

How does DNA purification work and what are its reagents?

1. Cells are broken up and release their contents

2. DNA is separated from debris

3. High salt concentrations cause DNA to bind to silica membrane in a column

4. A wash is added to remove proteins/waste again

5. A low salt buffer is added to the column, which releases the DNA to be collected

• You need enzymes to absorb waste, salts to neutralize DNA, and a buffer to rehydrate DNA

How does gel electrophoresis work?

1. When an electric current is applied to gel, DNA moves down towards the positive anode because DNA is negative

2. Larger fragments stay near the top and take longer to come down. The size is measured using a DNA ladder

What are the main components of a plasmid?

• Origin of replication: Act as the starting point for DNA replication

• Selectable marker: A gene that can tell you if a plasmid was successfully taken up by a cell or not