E2 Saliva protein II- Proteins/ SDS-PAGE

What is Gel Electrophoresis?

A technique used to separate DNA, RNA or protein molecules based on their size and net charge

Which direction do molecule move toward in Gel Electrophoresis?

From negative electrode to positive electrode

Which molecules move faster small with higher negative or big with higher positive charge?

Small and higher negative charge

Is Protein Electrophoresis similar to nucleic acid electrophoresis?

Similar but we must make some modifications to the proteins

What is an issue with protein charge in gel electrophoresis?

Proteins have various charges

Determined by AAs in polypeptide chain

What is a Zwitterion molecule?

A molecule that have both positive and negative charge on the amino acid, which creates a net neutral charge

What is SDS and its function?

Sodium dodecyl sulfate

A buffer to denatures 3D folding of the protein and give the protein a net negative charge

T/F: the darked the band, the larger protein concentration

True

Based on the “Protein” gel, how many different proteins can you identify in your saliva sample?

5 bands => 5 different proteins

Based on the “Amylase” gel, which band do you think contains the amylase protein?

Band E

What is the difference between Gel electrophoresis for nucleic acid and protein?

For nucleic acid, denaturing Gel electrophoresis is usually used which cuts DNA, and RNA into smaller fragments. For protein, native Gel electrophile is commonly used where protein is treated with detergent to get an overall negative charge.