Absorbance at Various PH Levels The Table Represents the Results of an Experiment Where the }

question 69

Multiple Choice

Absorbance at Various pH Levels
$\begin{array}{c}\begin{array}{|l|}\hline \text { Time (sec) } \\\hline20 \\\hline 40 \\\hline 60 \\\hline 80 \\\hline 100 \\\hline 120 \\\hline \end{array}\begin{array}{l|}\hline\mathrm{pH} \mathrm{4} \\\hline0.003\\\hline 0.009 \\\hline 0.012 \\\hline 0.020 \\\hline 0.023 \\\hline 0.025\\\hline \end{array}\begin{array}{l|}\hline\mathrm{pH} \mathrm{5} \\\hline0.025 \\\hline 0.109 \\\hline 0.195 \\\hline 0.215 \\\hline 0.333 \\\hline 0.360 \\\hline \end{array}\begin{array}{l|}\hline\mathrm{pH} \mathrm{6} \\\hline0.055 \\\hline 0.152 \\\hline 0.255 \\\hline 0.341 \\\hline 0.413 \\\hline 0.478 \\\hline \end{array}\begin{array}{l|}\hline\mathrm{pH} \mathrm{7} \\\hline0.146 \\\hline 0.300 \\\hline 0.432 \\\hline 0.552 \\\hline 0.659 \\\hline 0.755 \\\hline \end{array}\begin{array}{l|}\hline\mathrm{pH} \mathrm{8} \\\hline0.005 \\\hline 0.015\\\hline 0.038\\\hline 0.065\\\hline 0.081 \\\hline 0.090 \\\hline \end{array}\begin{array}{l|}\hline\mathrm{pH} \mathrm{9} \\\hline0.004 \\\hline 0.008\\\hline 0.010\\\hline 0.012\\\hline 0.013 \\\hline 0.013\\\hline \end{array}\end{array}$

The table represents the results of an experiment where the effects of pH buffers on an enzyme found in saliva (amylase) were studied. A spectrophotometer set at 500 nm was used to measure absorbance at the various pH levels every 20 seconds for 2 minutes. The higher absorbance values would indicate greater enzyme activity. All experiments were conducted at the same temperature.
Which statement correctly identifies the result that the optimum pH for amylase function is 7?

• A) The pH with the lowest absorbance values would indicate the optimum pH for amylase since this pH does not affect the structure or function of the protein.
• B) The pH with the highest absorbance values would indicate the optimum pH for amylase since this pH does not affect the structure or function of the protein.
• C) At pH 9, the enzyme is denatured and will lose its function, but not its structure.
• D) At pH 4, the structure of the enzyme will be altered, and the enzyme would not be able to catalyze the reaction.

---

Definitions:

Costs Paid

Expenses that a company has incurred and settled through payment.

Cash Basis

An accounting method where revenues and expenses are recognized only when cash is actually received or paid out, ignoring receivables and payables.

Expense Recognition

The accounting principle that expenses should be recognized in the period in which they are incurred, regardless of when payment is made.

Economic Life

The expected period during which an asset remains useful to a particular entity or project, often affecting its depreciation schedules.