FREE AND STUDY GAMES ABOUT BC351 EXAM QUESTIONS

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FREE AND STUDY GAMES ABOUT BC351 EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -108 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation

Question 1: Two molecules A and B have a KA =

106 M-1 for AB complex formation. When both molecules are at 10-8 M (10 nM) the proportion of A and B in an AB complex will be

Answer:

<10%

Question 2: An alpha helix is stabilized by

Answer:

Hydrogen bonds between every fourth amino acids in the helix

Question 3: In serine proteases, the Serine-195 hydroxyl group

Answer:

participates in covalent catalysis.

Question 4: Leventhal's paradox

Answer:

is solved by proteins folding in a step-wise, non random fashion.

Question 5: Protein-ligand binding is dependent on

Answer:

non-covalent interactions and proper fit

Question 6: In an alpha helix

Answer:

The R-groups are pointed outwards

Question 7: Rotational symmetry in proteins

Answer:

may occur around one or more axes

Question 8: Two molecules, A and B, have a KA = 106

M-1 for AB complex formation. When both molecules are at 10-5 M (10 ?M) the proportion of A and B in an AB complex will be

Answer:

>90% Question 9: Which of the following is least likely to result in protein denaturation?

Answer:

Changing the salt concentration

Question 10: Protein-ligand interactions are formed through

Answer:

many weak non-covalent interactions Question 11: Triosephosphate isomerase catalyzes the above reaction and is competitively inhibited by phosphoglycolate by

Answer:

acting as a transition state analog

Question 12: Concurrent acid and base catalysis

Answer:

involves making reactants better electrophiles and better nucleophiles.

Question 13: Which one of the following statements is true of enzyme catalysts?

Answer:

They lower the activation energy for the conversion of substrate to product.Question 14: An enzyme has a Vmax of 15?mols/min and and the reaction started with 5?mols of enzyme. What is the kcat of the reaction?

Answer:

3/min Question 15: The Ras protein being mutated in a cancer cell so that the protein function is always ON is an example of

Answer:

a gain of function mutation

Question 16: In the process of catalyzing a reaction, enzymes

Answer:

affect only ?G? (not ?G?).Question 17: Which of the following statements concerning rotational symmetry in proteins is false?

Answer:

It involves rotation of proteins inside the cell.Question 18: Anti-cancer drugs have become more specialized as they are designed to fit into the active site of particular enzymes. How do these ligands interact with their specific proteins?

Answer:

Through noncovalent intermolecular interactions

Question 19: What does an enzyme do?

Answer:

Catalyze reactions

Question 20: Multidrug resistance (MDR) in cancer cells

Answer:

often arises through expression of Pglycoprotein.

Question 21: Viral capsids often have which type of rotational symmetry?

Answer:

Icosahedral

Question 22: Which of the following is TRUE about 2,3-bisphosphoglycerate?

Answer:

It does not have a high binding affinity for fetal hemoglobin Question 23: In hemoglobin, the transition from T state to R state (low to high affinity) is triggered by

Answer:

oxygen binding.Question 24: A mutation in an enzyme?s active site that increases its affinity for the substrate 100-fold is most likely to

Answer:

reduce the rate of the catalyzed reaction

Question 25: The functional group likely to be found in a beta-turn is

Answer:

glycine

Question 26: Which has a greater affinity for an enzyme binding site?

Answer:

A transition state analog Question 27: In the binding of oxygen to myoglobin, the relationship between the concentration of oxygen and the fraction of binding sites occupied can best be described as

Answer:

hyperbolic.

Question 28: An assumption made in Michaelis-Menten kinetics is

Answer:

the enzyme is at a much lower concentration than the substrate