Protein Structure and Function Quiz

What is the primary structure of a protein?

• The 3-D shape of a single polypeptide chain

• The linear sequence of amino acids in a peptide

• The interaction between peptides in proteins

• The local structure of neighboring amino acids

Which type of bond stabilizes the secondary structure of proteins?

• Peptide bonds

• Ionic bonds

• Hydrogen bonds

• Covalent bonds

What is the role of proline in protein structure?

• Stabilizes the primary structure

• Forms disulfide bonds

• Interrupts secondary structure

• Enhances hydrophobic interactions

What occurs during the formation of a peptide bond?

• Hydrolysis reaction

• Dehydration reaction

• Oxidation reaction

• Reduction reaction

What is the isoelectric point (pI) of an amino acid?

• The pH at which an amino acid is fully protonated

• The pH at which an amino acid is fully deprotonated

• The pH at which an amino acid has no net charge

• The pH at which an amino acid is most acidic

What happens during protein denaturation?

• Formation of peptide bonds

• Loss of 3-D structure

• Increase in peptide length

• Stabilization of secondary structure

What is the role of enzymes as biological catalysts?

• They alter the ΔG or ΔH of a reaction.

• They change the rate of reaction by altering the mechanism.

• They are consumed in the reaction.

• They only catalyze forward reactions.

Which type of reaction involves the transfer of electrons?

• Transferases

• Hydrolases

• Oxidoreductases

• Lyases

What is the effect of temperature and pH on enzyme activity?

• They have no effect on enzyme activity.

• They can cause denaturing and loss of activity.

• They only affect enzyme activity in vitro.

• They increase enzyme activity indefinitely.

What happens in competitive inhibition?

• The inhibitor binds to the enzyme-substrate complex.

• The inhibitor binds at the active site.

• The inhibitor binds with equal affinity to the enzyme and enzyme-substrate complex.

• The inhibitor binds at an allosteric site.