An Experiment Is Performed in Which the Kinetics of an Enzyme-Catalyzed

question 32

Multiple Choice

An experiment is performed in which the kinetics of an enzyme-catalyzed reaction at different pHs is monitored.It is found that the K_m does not change but that the k_cat increases as the pH goes above 7.Which of the following is true?

• A) A chemical group within the enzyme that has a pKa of around 7 is likely involved in the catalytic mechanism.
• B) A chemical group with a pKa of around 7 must be deprotonated in order for substrate to bind.
• C) A chemical group with a pKa of around 7 must be positively charged in order for the substrate to bind.
• D) Protons are acting as positive heterotropic allosteric effectors of this enzyme.

---

Definitions:

Sea Anemones

Marine invertebrates known for their colorful, flower-like appearance and their symbiotic relationships with clownfish and other species.

Taxonomy

Taxonomy is the science of defining and naming groups of biological organisms on the basis of shared characteristics, often organized into a hierarchical classification.

Humans

Homo sapiens, the species of bipedal primates to which all modern human beings belong.

Climate Changes

Long-term alterations in temperature, precipitation, wind patterns, and other aspects of the Earth's climate system.