Theme 3.8

Functional relationships between proteins can best be determined from which of the following tools? Question 5 options: Sequence alignment Protein folding pathways Binding curves Structure alignment

Structure alignment

Heme is correctly described by which of the following terms? Question 2 options: Metal ion Myoglobin Cofactor Ligand

2

Which of the following statements describes heme? Question 1 options: A molecule covalently bonded to myoglobin A protein An organic molecule containing an iron center None of these

1

Which type of information can be learned from a structure alignment (select all correct answers)? Question 2 options: Secondary structure Tertiary structure Evolutionary relationships Primary structure

12

Which of the following molecules is a protein with an oxygen transport function (select all correct answers)? Question 5 options: Myoglobin Immunoglobulin Hemoglobin Heme

134

Affinity is described by which of the following statements? Question 5 options: Whether a protein is correctly structured to perform its function The dissociation constant Complementarity How strongly two molecules bind together

2

Which of the following terms describes how strongly two molecules interact non-covalently? Question 1 options: Complementarity Saturation Affinity Bonding

3

The Kd is which of the following terms? Question 1 options: Binding constant Unbinding constant Dissociation constant Association constant

Dissociation constant

Y represents which of the following concepts? Question 4 options: Fraction of protein bound to ligand Fraction of ligand bound to protein The dissociation constant The concentration of ligand at half-saturation

Fraction of protein bound to ligand

Both protein A and protein B bind to molecule C. Protein A has higher affinity for C than protein B does. Protein A therefore has a lower value than protein B for which of the following terms? Question 3 options: None of these Y pO2 Kd

Kd

Which of the following terms indicates when all protein molecules are bound to ligand? Question 1 options: Kd Saturated None of these Affinity

Kd

Protein Z binds both molecule A and molecule B. Molecule A has a larger Kd than molecule B. Which molecule has the higher affinity? Question 5 options: Molecule A There is insufficient information to answer this question Protein Z Molecule B

Molecule B

Which of the following terms describes the amount of oxygen present? Question 2 options: Kd pO2 None of these Y

pO2

Protein P binds ligand L. If the fractional saturation is 0.30, which of the following statements is true? Question 3 options: The Kd is less than [L] 30% of P is bound to L 30% of L is bound to P The [P] is less than the Kd

30% of P is bound to L

Which of the following statements correctly interprets the Kd? Question 5 options: The saturation of the protein at any value of ligand The value of the equilibrium constant for the association of the protein and ligand The concentration of ligand when [protein bound to ligand] = [protein notbound to ligand] None of these

4

Hemoglobin is correctly described by which of the following statements? Question 4 options: A protein formed from four myoglobin subunits An oxygen transport protein A ligand that binds to a heme group to be delivered to cells A tetramer of myoglobin

An oxygen transport protein

Which type of information can be learned from a structure alignment (select all correct answers)? Question 2 options: Similarities and differences in structure between two proteins The identity of ligands that a protein binds Primary structure of a newly discovered protein Tertiary structure of an newly discovered protein

Similarities and differences in structure between two proteins

Structural alignments can provide which of the following information? Question 3 options: Similarities in protein secondary structure Similarities in protein primary structure Differences in protein function All of these

Similarities in protein secondary structure

The reaction of a protein and ligand associated with a Kd has which form? Question 2 options: It depends on the particular reaction Protein + Ligand → Protein-Ligand Protein-Ligand → Protein + Ligand Protein-Ligand + H2O → Protein + Ligand

Protein-Ligand → Protein + Ligand

Which of the following scenarios is true when a protein is saturated? Question 4 options: All of the protein in solution is bound to ligand The protein does not contain any double bonds None of the protein in solution is bound to ligand The protein is full of water

The protein does not contain any double bonds

Which of the following expressions is equal to the Kd for protein M binding to ligand Q? Question 3 options: [M-Q complex]/([M][Q]) [Q]/([M][M-Q complex]) None of these ([M][Q])/[M-Q complex]

([M][Q])/[M-Q complex]

When a protein is saturated, which of the following statements is true? Question 3 options: All of the ligand is bound to protein The concentration of ligand is equal to the Kd None of the ligand binding sites are occupied All of the ligand binding sites are occupied

All of the ligand binding sites are occupied

When a protein is saturated, which of the following statements is true? Question 4 options: None of these All of the ligand binding sites are occupied Half of the ligand binding sites are occupied None of the ligand binding sites are occupied

All of the ligand binding sites are occupied

Which of the following statements describes fractional saturation (Y)? Question 4 options: The fraction of protein bound to ligand The fraction of ligand bound to protein How much additional ligand is needed to reach saturation The dissociation constant

The fraction of protein bound to ligand