Amino Acids
Polypeptides
Secondary Structure
Tertiary/Quaternary Structure
Hemoglobin
100
Draw the basic structure of an amino acid.
100
Which bonds have rotation? Which don't?
Phi (Φ) and Psi (Ψ) bonds rotate, peptide bonds do not.
100
Draw a parallel beta-pleated sheet.
100
(T/F) Proteins with only one subunit can exhibit cooperativity.
False.
100
Which Hb conformation has a lower binding affinity for O2?
T-state
200
Calculate the pI of Isoleucine
6.04
200
What is produced when a peptide bond is formed? What is this reaction called?
H2O is produced, called a condensation reaction
200
The majority of alpha helices are ____-handed and contain ___-enantiomers.
Right, L
200
What force drives Tertiary/Quaternary folding?
The hydrophobic effect.
200
Draw the Oxygen affinity curves for Hemoglobin and Myglobin.
300
Calculate the pI of Arginine
10.74
300
Label the N and C termini of the following polypeptide.
N-terminus is on the right, C-terminus is on the left.
300
Which amino acids are typically found in beta turns?
Proline and Glycine.
300
Which intermolecular forces are found in both secondary and tertiary structure?
Hydrogen bonds.
300
List the 4 stabilizers of the T-state.
high [CO2], Low pH, High [BPG], low O2
400
List the 7 ionizable amino acids
Lysine, Arginine, Histidine, Aspartic acid, Glutamic acid, Tyrosine, and Cysteine.
400
Calculate the pI of the polypeptide Val - Leu - Glu - Gln
3.12
400
Where is the following segment of polypeptide likely located on a protein? Lys - Asp - His - Thr - Gly
One the outside of the polypeptide (exposed to water).
400
List the intermolecular forces that stabilize tertiary and quaternary structure.
Hydrogen bonding, disulfide bonds, salt bridges, and Van der Waals interactions
400
Which form of hemoglobin is shown below? (R or T)
R-state
500
Calculate the charge of tyrosine at a pH of 3
+0.137
500
Draw a pH vs. Charge plot for the polypeptide Met - Glu - His - Trp
500
Where is the following segment of polypeptide likely located on a protein? Arg - Val - Thr - Ile - Tyr
Amphipathic beta pleated sheet.
500
Draw an example of an unfolded protein in water. What is formed?
Clathrate
500
A mutation occurs that decreases the number of positive groups in the inner channel of Hb to 7. How is Oxygen binding affected?
Hb's affinity for O2 is increased.