L3 Protein and Activity Quiz

Evelyn comes across alanine, and wonders, which of the following is the L-isomer of alanine?

• NH₂ on the right

• NH₂ on the left

• 
  Both are L-isomers

• 
  Neither is correct

Isla learned that a specific type of reaction is responsible for forming peptide bonds between amino acids. What type of reaction is she studying?

• Hydrolysis

• 
  Condensation

• 
  Oxidation

• 
  Reduction

What functional group is involved in forming a peptide bond?

• Hydroxyl and amine

• 
  Amine and carboxyl

• Carbonyl and hydroxyl

• 
  Methyl and carbonyl

Name the dipeptide.

• Gly-Val

• Phe-Gly

• Phe-Phe

• Val-Phe

How many peptide bonds are present in the tetrapeptide Gly-His-Ser-Ala?

• 4

• 
  1

• 3

• 2

Which statement about peptide bond resonance is true?

• Peptide bonds rotate freely

• Peptide bonds have partial double bond character

• Only primary amines can form peptide bonds

• The peptide bond is always positively charged

What is the main consequence of the partial double-bond character of a peptide bond?

• It increases the bond's flexibility

• It makes the bond more reactive to hydrolysis

• It restricts free rotation around the bond

• It allows the bond to rotate freely

Which atoms are primarily involved in the resonance of a peptide bond?

• Alpha carbon, amine nitrogen, and R-group

• Carbonyl carbon, oxygen, and amide nitrogen

• Sulfur, amine nitrogen, and hydrogen

• Hydrogen, carboxyl oxygen, and peptide nitrogen