Mechanisms Of Enzyme Action - Biochemistry | Biology+

Course

Biochemistry

Study Pack

Set 1: The Facts of Life: Chemistry Is the Logic of Biological Phenomena

Set 2: Water: the Medium of Life

Set 3: Thermodynamics of Biological Systems

Set 4: Amino Acids and the Peptide Bond

Set 5: Proteins: Their Primary Structure and Biological Functions

Set 6: Proteins: Secondary, Tertiary, and Quaternary Structure

Set 7: Carbohydrates and the Glycoconjugates of Cell Surfaces

Set 9: Membranes and Membrane Transport

Set 10: Nucleotides and Nucleic Acids

Set 11: Structure of Nucleic Acids

Set 12: Recombinant Dna, Cloning, Chimeric Genes, and Synthetic Biology

Set 13: Enzymeskinetics and Specificity

Set 14: Mechanisms of Enzyme Action

Set 15: Enzyme Regulation

Set 16: Molecular Motors

Set 17: Metabolism: an Overview

Set 18: Glycolysis

Set 19: The Tricarboxylic Acid Cycle

Set 20: Electron Transport and Oxidative Phosphorylation

Set 21: Photosynthesis

Set 22: Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

Set 23: Fatty Acid Catabolism

Set 24: Lipid Biosynthesis

Set 25: Nitrogen Acquisition and Amino Acid Metabolism

Set 26: Synthesis and Degradation of Nucleotides

Set 27: Metabolic Integration and Organ Specialization

Set 28: Dna Metabolism: Replication, Recombination, and Repair

Set 29: Transcription and the Regulation of Gene Expression

Set 30: Protein Synthesis

Set 31: Completing the Protein Life Cycle: Folding, Processing, and Degradation

Set 32: The Reception and Transmission of Extracellular Information

Set 14 Mechanisms Of Enzyme Action

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Set 14 Mechanisms Of Enzyme Action

(Multiple Choice)

Free

In the hydrolysis of p-nitrophenylacetate by chymotrypsin all of the following are correct EXCEPT:

A) the first product is acetic acid.
B) an acetyl-enzyme intermediate forms during the mechanism.
C) attack of a water molecule on the acyl-enzyme intermediate yields the second product.
D) the active site contains a serine residue, an unprotonated histidine, and an unprotonated aspartate residue at pH 7.0 prior to binding the substrate.
E) none of the above.

Answer

(Multiple Choice)

Free

In the catalytic triad common to many serine proteases, _____ increases the basicity of _____, thus allowing deprotonation of _____ to serve as a nucleophile.

A) Ser-His-Asp
B) His-Ser-Asp
C) Ser-His-His
D) Asp-His-Ser
E) Cys-His-Ser

Answer

(Multiple Choice)

Free

All are true for low-barrier hydrogen bonds EXCEPT:

A) The hydrogen is centered between the two heteroatoms.
B) The interactions are more covalent.
C) The bond order approaches 0.5 for both O−H interactions.
D) The barrier that the hydrogen atom must surmount to exchange oxygens becomes lower.
E) All are true.

Answer