As food travels through the digestive system it is exposed to a variety of ph levels. the stomach has a ph of 2 due to the presence of hydrochloride acid and the smallest intestine has a ph ranging from 7 to 9. hci converts pepsinogen into pepsin an enzyme that digests proteins in the stomach. which of the following most likely happens to pepsin as it enters the small intestine.
the pepsin begins to replicate
the pepsin’s activity increases to digest more proteins
the pepsin becomes inactive
the pepsin’s shape changes to engulf large proteins

The answer is C. Pepsin becomes inactive as soon as it reaches small intestine.

Explanation:

Enzymes are pH specific. They once work at those specific values and if those are changed they either degrade or become inactive. The pH of stomach is acidic and that of the small intestine is basic. Therefore the enzymes will become inactive when it enters small intestine.

"a scientist studying a whale and its surroundings would need to understand the structure of atoms in case something was negatively affecting the whale or its surroundings."

explanation:

this was from the link provided:

then that particular organisms become extinct.