Title: Quiz: SDS-PAGE
Course: BTEC-2020-301-302-303-F21 > Section: Protein Gels

Q: How many characteristics of a protein strongly influence its migration through a nondenaturing gel?
- 4 characteristics: mass, shape, charge, and function (Incorrect. The function of a protein does not affect its migration through a gel.)
- 3 characteristics: mass, shape, and charge (Correct. Mass, shape, and charge all influence the migration of a protein through a nondenaturing gel.)
- 2 characteristics: shape and charge (Incorrect. While shape and charge do influence the migration of a protein through a nondenaturing gel, the mass of a protein is also a factor.)
- 1 characteristic: mass (Incorrect. Mass is one of three factors that influence a protein’s migration through a nondenaturing gel)
A: 3 characteristics: mass, shape, and charge

Q: How many characteristics of a protein strongly influence its migration in SDS-PAGE?
- 4 characteristics: mass, shape, charge, and function (Incorrect. The function of a protein does not affect its migration through a gel. Also, the goal of SDS-PAGE is to make all proteins roughly the same shape and charge, so that mass alone determines migration.)
- 3 characteristics: mass, shape, and charge (Incorrect. In a nondenaturing gel, mass, shape, and charge all influence migration. In SDS-PAGE, the goal is to make all proteins roughly the same shape and charge, so that mass alone determines migration.)
- 2 characteristics: shape and charge (Incorrect. The goal of SDS-PAGE is to make all proteins roughly the same shape and charge, so that mass alone determines migration.)
- 1 characteristics: mass (Correct. The goal of SDS-PAGE is to make all proteins roughly the same shape and charge, so that mass alone determines migration.)
A: 1 characteristics: mass

Q: What is the meaning of denature as it applies to proteins?
- To destroy the shape of a protein (Correct. Denaturing a protein disrupts secondary, tertiary, and quaternary structure.)
- To cause the proteins in a gel to form tight bands (Incorrect. Denaturing a protein disrupts secondary, tertiary, and quaternary structure. Stacking is the process that causes proteins to form tight bands in a gel.)
- To determine the charge of a protein (Incorrect. Denaturing a protein disrupts secondary, tertiary, and quaternary structure.)
- To change the amino acid sequence of a protein (Incorrect. Denaturing a protein disrupts secondary, tertiary, and quaternary structure. Amino acid sequence is primary structure, and is not affected by denaturation.)
A: To destroy the shape of a protein

Q: How many treatments are applied to minimize the influence of protein shape on migration in SDS-PAGE?
- 4 treatments: SDS, DTT, boiling, and stacking (Incorrect. SDS, DTT, and boiling all denature proteins, which minimizes the influence of shape. Stacking makes gels have tighter bands, but does not denature proteins.)
- 3 treatments: SDS, DTT, and boiling (Correct. SDS, DTT, and boiling all denature proteins, which minimizes the influence of shape.)
- 2 treatments: SDS and boiling (Incorrect. SDS and boiling do denature proteins, which minimizes the influence of shape. However, DTT also denatures proteins by breaking disulfide bonds.)
- 1 treatment: SDS (Incorrect. SDS does help denature proteins. However, DTT and boiling also assist in denaturing.)
A: 3 treatments: SDS, DTT, and boiling

Q: How many treatments are applied to minimize the influence of protein charge on migration in SDS-PAGE?
- 4 treatments: SDS, DTT, boiling, and stacking (Incorrect. DTT, boiling, and stacking do not influence the charge of a protein.)
- 3 treatments: SDS, DTT, and boiling (Incorrect. DTT and boiling do not influence the charge of a protein.)
- 2 treatments: SDS and boiling (Incorrect. Boiling does not influence the charge of a protein.)
- 1 treatment: SDS (Correct. SDS coats proteins with strong negative charges, overwhelming the effect of the protein’s native charge.)
A: 1 treatment: SDS