The Image Below Diagrams the Action of an Enzyme

question 55

Multiple Choice

The image below diagrams the action of an enzyme.Notice that the enzyme is depicted as being more tightly wrapped around the substrates in step 2 than it is in step 1.Why is this?

• A) When a substrate locks into the active site of an enzyme,the enzyme changes shape to mold itself around the substrates.
• B) Generally,the size of a substrate is larger than the size of the active site into which it must fit.When the substrate enters the active site,the active site must stretch to fit.
• C) Before catalysis can occur,a substrate must change its shape so that it fits into the active site of the enzyme more precisely.
• D) Most active sites are only designed to hold one substrate.In this image,two substrates enter the active site,creating a tighter fit.

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Definitions:

Variable Overhead Rate Variance

The difference between the actual variable overheads incurred and the expected variable overheads based on standard rates.

Labor Rate Variance

The difference between the actual labor rate paid and the standard rate expected, multiplied by the total hours worked.

Labor Efficiency Variance

The variance between the real hours spent producing a good or service and the anticipated standard hours, times the standard wage rate.

Variable Overhead Rate Variance

The difference between the actual variable overhead costs incurred and the standard variable overhead expected for the actual production achieved.