WorksheetsL3-L6 Supplemental Practice
Total questions: 23
Worksheet time: 4hrs 50mins
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
Which amino acid is usually most abundant in proteins? Which one is usually least abundant?
Most: I
Least: W
Most: L
Least: Y
Most: L
Least: W
Most: P
Least: Y
Which peptide torsional angle(s) is restricted to 180 degrees?
Phi & Psi
Phi
Omega & Psi
Omega
All of the above
Which of the following answer choices properly classifies the polypeptide torsional angles?
Φ: N-Cα
Ψ: Cβ- Cα
Ω: C-N
Φ: Cα- C
Ψ: N-Cα
Ω: C-N
Φ: C-N
Ψ: Cα- C
Ω: N-Cα
Φ: N-Cα
Ψ: Cα- C
Ω: C-N
In lecture Dr.McKenna mentioned a specific interaction that stabilizes alpha helices. What interaction did he mention?
Van der Waals interactions
Covalent Bonds
Hydrogen Bonds
Hydrophobic interactions
What was the narrowest type of alpha helix we discussed in lecture?
310
α
π
They are all the same width
The vertical solid lines below represent the strands of a B-sheet. The dotted lines represent the hydrogen bonding pattern between the strands of the sheet, Assume the arrow head on the first strand (on the left) represents the direction of the polypeptide chain.
Based ONLY on the H-bond pattern, which of the following sets of arrows, best describes the direction of the strands going from left to right?
↑↓↑↑↑↓
↑↑↑↓↑↑
↑↓↑↓↑↓
↑↓↑↑↑↑
Which of the following amino acids are usually found in reverse turns?
GSASL
VIFYWT
ACLMEQHK
GSDNP
Which of the following is a polar amino acid?
Threonine
Aspartate
Alanine
Valine
What is the the value of ΔS of the protein water system when protein folding occurs?
Negative
Positive
What is the term that we use to describe the intermediate inn the protein folding process?
Random coil
α -helices
Molten Globule
β sheet
Which of the following non-covalent interactions was said to be the driving force of protein folding?
Van der Waals interactions
H-bonds
Hydrophobic interactions
Electrostatic Interactions
Disulfide bonds
Two cysteines are _________ to create a disulfide bond.
Oxidized
Reduced
None of the above
All of the above
What term refers to some proteins ability to spontaneously refold into their native 3D structure?
Renaturation
Denaturation
Cross-linking
None of the above
