Biochemistry Protein Structure and Function 2

Question 1

What is the isoelectric point (pI) of a protein?

Accepted Answer

The pH at which the protein carries no net charge

Answer

The pH at which the protein has maximum solubility

Answer

The pH at which the protein denatures

Answer

The pH at which the protein has maximum enzymatic activity

Question 2

Chaperone proteins assist in which process?

Accepted Answer

Correct protein folding

Answer

Protein degradation

Answer

mRNA translation initiation

Answer

Post-translational glycosylation

Question 3

Which prosthetic group is found in myoglobin and hemoglobin, enabling oxygen binding?

Accepted Answer

Heme group

Answer

Flavin adenine dinucleotide (FAD)

Answer

Pyridoxal phosphate (PLP)

Answer

Biotin

Question 4

The cooperative binding of oxygen to hemoglobin is best described by which model?

Accepted Answer

Concerted (MWC) model

Answer

Lock-and-key model

Answer

Induced fit model

Answer

Michaelis-Menten model

Question 5

2,3-Bisphosphoglycerate (2,3-BPG) affects hemoglobin oxygen binding by:

Accepted Answer

Decreasing oxygen affinity by stabilizing the T state

Answer

Increasing oxygen affinity by stabilizing the R state

Answer

Blocking the heme iron from binding oxygen

Answer

Promoting dissociation of hemoglobin subunits

Question 6

Which technique separates proteins based on their isoelectric points?

Accepted Answer

Isoelectric focusing

Answer

SDS-PAGE

Answer

Size-exclusion chromatography

Answer

Affinity chromatography