Unit 4.1

Question 1

Why is protein purification required?

Answer 1

to study structure and function

Question 2

What challenges come with purifying proteins?

Answer 2

• the mixture of proteins in cells/tissue
• diversity of proteins (such as size, charge, binding characteristics, and cellular location)

Question 3

what determines a protein’s separation/purification parameters and assay?

Answer 3

It’s size, charge, binding characteristics and cellular location

Question 4

What is the order of the protein purification workflow?

Answer 4

1. identify source (blood, cell type, etc)
2. fractionation/enrichment (by centrifugation or salt fractionation)
3. Purification
4. monitoring purification (gel electrophoresis)
5. quantification (protein concentration or enzyme activity)
6. analysis (structure and function)

Question 5

how does gel electrophoresis work?

Answer 5

molecules are separated in electrical field through a porous field acting as a molecular sieve.

Question 6

what medium is usually used?

Answer 6

Polyacrylamide (proteins) and sometimes Agarose for nucleic acids

Question 7

What type of proteins is electrophoresis used for?

Answer 7

both native and denatured, but mostly denatured