Both the esophagus and the small intestine are involved in the digestion of food. The esophagus squeezes food into the stomach b
y wave-like muscle contractions. Peptidase enzymes in the small intestine break food molecules into smaller molecules. Which statement best describes changes to food during digestion?
A. The muscle contractions result in physical changes, while the action of the peptidase results in chemical changes.
B. The muscle contractions result in chemical changes, while the peptidase results in physical changes.
C. The muscle contractions and the action of the peptidase both result only in physical changes.
D. The muscle contractions and the action in the peptidase both result only in chemical changes.
The wave-like contractions are to be considered a physical change as they do not take part in the breaking-down of the food. The peptidase is a chemical change because it is used to chemically break down the food to retrieve nutrients and such.
