L3-L6 Supplemental Practice

Imagine that you have three proteins. The molecular weights of the proteins are as follow:

Protein A: 36000 g/mol

Protein B: 30000 g/mol

Protein C: 32000 g/mol

The diagram shows a gel electrophoresis plate with three lines that represent proteins. Where do you predict Protein A would present?

• Top Line

• Middle Line

• Bottom Line

• None of the above, gel electrophoresis is for DNA

What amino acid below is achiral?

• 
• 
• 
• 

Is the following amino acid in the L or D configuration?

• L-configuration

• D-configuration

Which of the following are hydrophobic amino acids? Select all that apply.

• Glycine

• Cysteine

• Isoleucine

• Glutamine

• Serine

Rank the aromatic amino acids from lowest to highest UV Light Absorbance

• Phenylalanine,

  Tryptophan, Tyrosine

• Tyrosine, Phenylalanine, Tryptophan

• Phenylalanine,

  Tryptophan,

  Tyrosine

• Phenylalanine,

  Tyrosine,

  Tryptophan

What is the name of this amino acid?

• Asparagine

• Glutamine

• Glutamate

• Aspartate

What is the length of the peptide bond in amino acids?

• 1.30 A

• 1.32 A

• 1.35 A

• 1.31 A

What amino acids make up this tripeptide in order from left to right?

• Glycine,

  Valine,

  Isoleucine

• Alanine,

  Valine,

  Leucine

• Proline,

  Alanine,

  Aspartate

• Leucine,

  Proline,

  Aspartate

Determine the isoelectric point (pI) of the following polypeptide: Gly-Glu-Ala-Trp-Lys

pKa values:

Ala: 2.34, 9.69

Glu: 2.13,4.25,9.67

Gly: 2.34,9.60

Lys: 2.18, 8.95, 10.53

Trp: 2.83, 9.39

• 6.93

• 10.07

• 3.22

• 9.58

• 2.08

Hemoglobin is a tetramer with 2 alpha chains and 2 beta chains. The alpha chains have 141 amino acid residues each and the beta chains have 146 amino acid residues each. Given this information estimate the molecular weight of hemoglobin.

• 73,472

• 574

• 63,140

• None of the above