Exam 11: Enzyme Catalysis

The enzyme pictured below is shown in two configurations,A (open)and B (closed).Upon binding substrate in the active site,the enzyme converts the structure shown in B.Which of the following is true based on the given information?

Alcohol dehydrogenase catalyzes the conversion of methanol to _________ and is,therefore,classified as a(an)________.

Matching -Metal ion cofactors offer various ______ states that allow enzymes to accomplished oxidation reduction reactions.

Curved arrows are conventionally used to illustrate the movement of

Consider the Schiff base formation reaction discussed in the catalytic mechanisms section of the chapter.What would probably happen if the carboxylate group was stabilized by a nearby positive charge?

A new serine protease was discovered that preferentially cleaves a peptide bond adjoining a negatively charged side chain.Which of the following is true?

The catalytic mechanism of bovine pancreatic RNase A relies upon acid-base catalysis involving the amino acid __________.

Matching -Clustering several amino acid residues with appropriate pK values at an active site can promote a(n)_________ catalytic mechanism.

Matching -On a transition state diagram for a one-step very spontaneous reaction a large peak (high $\Delta$ G^‡)would imply a ______ rate for the reaction.

Proton transfer from an acid,lowering the free energy of a reaction's transition state,is characteristic of

In the serine protease trypsin,the specificity for one substrate over another describes what type of catalysis?

Which one of the following is correct? (I)All enzymes are highly specific for the reactions they catalyze. (II)Prosthetic groups are loosely associated with the polypeptide chain of an enzyme. (III)If an enzyme-catalyzed reaction requires a group with a low pK to be deprotonated and a group with a higher pK to be protonated,the pH vs.rate curve will have a peak in the middle of the two pK values. (IV)When comparing types of catalysis,the proximity effect provides the largest rate enhancement.

The following diagram shows a portion of a reaction sequence of an enzyme.What type(s)of catalysis is (are)occurring in this first step?

A peptide with the sequence "Glu-Ser-Val-Asp-Lys" will likely be cut next to "Val" rapidly by _______ and very slowly by ____. (I)chymotrypsin (II)trypsin (III)trypsinogen (IV)elastase

Matching -On a transition state diagram for a multistep reaction,the step with the greatest $\Delta$ G is the ______.

Which of the following is TRUE about enzymes? (I)Enzymes typically catalyze reactions at much higher rates than chemical catalyst. (II)Enzymes are often very specific for their substrates. (III)Enzyme activities can often be regulated. (IV)Enzymes typically act under milder conditions of temperature and pH than chemical catalysts.

Lysozyme requires _____ for effective catalysis. (I)an Asp in a nonpolar environment (II)a negatively charged Asp (III)a Glu that functions as an acid catalyst (IV)a Glu that is deprotonated

Which of the following processes would yield and increase in rate?

Which of the following is TRUE regarding transition state?

Matching -If an enzyme-catalyzed reaction has a low rate at low pH and high rate at higher pH,this implies that a group on either the enzyme or the substrate must be ______ for an efficient reaction.