Question

question 7
1 pts
the hormone thought to be a messenger causing release of digestive enzymes from the intestinal mucosa is:
vasoactive intestinal peptide.
enterogastrone.
secretin.
cholecystokinin-pancreozymin.
question 8
1 pts
which of the following is not true of enzymes?
they accelerate chemical reactions.
they change chemically and are in the end products of the reaction.
they are vital to chemical reactions.
many contain vitamins in their structure.
question 9
1 pts
when classified according to the kind of chemical reactions catalyzed, digestive enzymes are referred to as ______ enzymes.
oxidation-reduction
hydrolyzing
phosphorylating
hydrase

Explanation:

Question 7

To determine the hormone that causes the release of digestive enzymes from the intestinal mucosa, we analyze each option:

• Vasoactive intestinal peptide: Involved in vasodilation and gut motility, not enzyme release.
• Enterogastrone: Inhibits gastric secretion, not enzyme release.
• Secretin: Stimulates bicarbonate release from the pancreas, not digestive enzymes.
• Cholecystokinin - pancreozymin (CCK - PZ): Stimulates the release of digestive enzymes from the pancreas (and intestinal mucosa - related enzyme release in digestion).

We analyze each statement about enzymes:

• "They accelerate chemical reactions": True, enzymes are catalysts.
• "They change chemically and are in the end products of the reaction": False, enzymes are not consumed or chemically changed in the reaction; they remain unchanged.
• "They are vital to chemical reactions": True, many biochemical reactions need enzymes.
• "Many contain vitamins in their structure": True, coenzymes (often vitamins) are part of some enzymes.

Digestive enzymes break down food molecules (like carbohydrates, proteins, fats) by adding water (hydrolysis).

• Oxidation - reduction enzymes: Involved in redox reactions, not digestion.
• Hydrolyzing enzymes: Use water to break bonds, which is what digestive enzymes do.
• Phosphorylating enzymes: Add phosphate groups, not related to digestion.
• Hydrase: Involved in adding/removing water in non - digestive reactions (e.g., hydration/dehydration of molecules), not digestion.

Answer:

D. cholecystokinin - pancreozymin.

Question 8