Question 1

Which of the following correctly ranks the strength of chemical bonds from strongest to weakest in biological molecules?

Accepted Answer

Covalent bond \u003e Ionic bond \u003e Hydrogen bond \u003e van der Waals interactions

Question 2

Which property of water is MOST responsible for its ability to dissolve ionic compounds?

Accepted Answer

Its polarity and ability to stabilize ions via hydration shells

Question 3

A protein is found to have a high proportion of hydrophobic amino acids on its surface. Which of the following is the most likely environment for this protein?

Accepted Answer

Lipid bilayer or membrane

Question 4

Which equation is used to relate pH, pKa, and the ratio of conjugate base to acid in a buffer system?

Accepted Answer

$$pH = pK_a + \log_{10} \left( \frac{[A^-]}{[HA]} \right)$$

Question 5

If the concentration of $$CO_2 in $$the blood increases, what is the expected effect on blood pH according to the bicarbonate buffer system?

Accepted Answer

Blood pH will decrease

Question 6

During a titration of glycine, which has two ionizing groups, how many equivalents of base are required to fully titrate both groups?

Accepted Answer

Two equivalents

Question 7

Which level of protein structure is primarily stabilized by hydrogen bonds between backbone atoms?

Accepted Answer

Secondary structure

Question 8

Which of the following best describes a protein domain?

Accepted Answer

A region of a protein that folds independently and has a specific function

Question 9

Which purification technique separates proteins based on their size?

Accepted Answer

Size exclusion chromatography

Question 10

What is the main function of myoglobin in muscle tissue?

Accepted Answer

Storing oxygen for use during muscle contraction

Question 11

Hemoglobin exhibits cooperative binding of oxygen. Which of the following best explains this phenomenon?

Accepted Answer

Binding of one oxygen molecule increases the affinity for subsequent oxygen molecules

Question 12

Which of the following equations represents the equilibrium for the bicarbonate buffer system in blood?

Accepted Answer

$$CO_2 + H_2O$$ \rightleftharpoons H_2CO_3 \rightleftharpoons H^+ + $$HCO_3$$^-$$

Question 13

A patient has a blood pH of 7.1 and elevated $$CO_2$$ levels. Which condition is most likely present?

Accepted Answer

Respiratory acidosis

Question 14

Which of the following statements about the Henderson-Hasselbalch equation is correct?

Accepted Answer

It can be used to calculate the pH of a solution given the concentrations of acid and base

Question 15

Which of the following best explains the difference between a motif and a domain in protein structure?

Accepted Answer

A motif is a small structural element, while a domain is a larger, independently folding region

Question 16

During SDS-PAGE, what is the primary factor that determines the migration of proteins through the gel?

Accepted Answer

Protein size (molecular weight)

Question 17

Which of the following is TRUE regarding the oxygen binding curves of myoglobin and hemoglobin?

Accepted Answer

Hemoglobin has a sigmoidal curve, myoglobin has a hyperbolic curve

Question 18

Which of the following best describes the effect of CO binding to hemoglobin?

Accepted Answer

CO binding increases hemoglobin's affinity for oxygen and prevents oxygen release in tissues

Question 19

A solution contains 0.1 M acetic acid ($$CH_3COOH) $$and 0.1 M sodium acetate ($$CH_3COONa). If $$the $$pK_a of $$acetic acid is 4.76, what is the pH of the solution?

Accepted Answer

$$pH = 4.76$$

Question 20

Which of the following statements about the quaternary structure of proteins is correct?

Accepted Answer

It involves the association of multiple polypeptide chains into a functional protein complex

Biochemistry Study Guide: Molecular Interactions, Protein Structure, and Oxygen Transport

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