Enzymes
The proteolysis rate enhancement by chymotrypsin (~1010 folds) corresponds to a reduction in activation energy of about

58 kJ/mol
49 kJ/mol
88 kJ/mol
40 kJ/mol

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Enzymes
In the enzyme-catalyzed reaction shown below, what will be the effect on substances A, B, C, and D of inactivating the enzyme labeled E2? A ---(E1)---> B ---(E2)---> C ---(E3)--->

A and B will still be produced, but not C or D
A, B, C, and D will all still be produced
A, B, and C will still be produced, but not D
A will still be produced, but not B, C, or D

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Enzymes
Which of the following statements about enzymes or their function is true?

Enzymes speed up reactions by lowering activation energy
Enzymes do not alter the overall change in free energy for a reaction
All of these
Enzymes are proteins whose three-dimensional form is key to their function

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Enzymes
Before they can react, many molecules need to be destabilized. This state is typically achieved through

changing the reaction from a biosynthetic to a catabolic pathway
oxidizing the molecules by removing electrons
changing the three-dimensional shape of the molecule
the input of a small amount of activation energy

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Enzymes
Which of the following is false statement with regard to comparison between Serine and HIV proteases?

Both forms an acyl-enzyme intermediate
Both require water to complete the catalytic cycle
Both show specificity for certain amino acid sequences
Both use nucleophilic attack to hydrolyze the peptide bond

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Enzymes
The cleavage specificity of trypsin and chymotrypsin depend in part on the

absence of water in the active site
presence of a low-barrier hydrogen bond in the active site or specificity pocket
proximity of Ser 195 to the active site or specificity pocket
size, shape, and charge of the active site or specificity pocket

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