Enzymes and Energy
In general, enzymes are protein molecules which must be folded in a specific three-dimensional shape in order to function properly. Certain environmental parameters can affect enzyme activity, including pH and temperature. If an enzyme’s shape changes significantly and it can no longer function, the enzyme is said to have become denatured.
The enzyme pancreatic amylase is manufactured and secreted by the pancreas into the duodenum (the large, beginning portion of the small intestine). Pancreatic amylase breaks down starch into maltose, a disaccharide. Pepsin is an enzyme that is released by the epithelium of the stomach, and functions in the stomach to break down proteins into smaller polypeptide units.
The following graphs show the activities of various enzymes under various environmental conditions.
Which curve illustrates the functioning of DNA polymerase from a shark?
|D||None of the above, since sharks, like all fish, do not contain DNA polymerase.|
Since sharks are fish, they are ectothermic and will assume the temperature of their environment. While there is no way for you to know exactly what this value is, it is certainly colder than 370 C, and the optimal temperature of the enzyme shown in graph A, about 120 C (about 500 F), is reasonable for cool water, since you have to pick one choice. D cannot be true; everything that is alive must contain a DNA polymerase!!