Enzyme and Digestion Practice
Name ____________________________ Hour _____
pH: Acids and Bases
1. Acids range in pH from ______1______ to _____6.99_____.
2. An example of an acid is ____battery acid, citrus fruits, toilet bowl cleaner_______.
3. Bases range in pH from _____7.1_____ to _____14_____.
4. An example of a base is ____soaps, lye, baking soda, windex______.
5. A neutral pH would be ___7.0_____.
6. An example of a substance with a neutral pH is ____distilled water______.
7. What role do acids play in digestion?
They are found in the stomach and help break down larger molecules into smaller molecules that
can be absorbed later in the digestive process. This would be an example of a hydrolysis reaction.
8. Would acids and bases be involved in Mechanical or Chemical digestion? __chemical__
9. Would acids and bases be involved in Condensation or Hydrolysis reactions? ___Hydrolysis____
Digestion
10. Label the following organs on the diagram to the right:
Stomach, Small Intestine, Large Intestine, Mouth, Esophagus,
Pancreas, Liver, Gall Bladder.
Esophagus
11. Explain the role each of these organs plays in chemical and/or
mechanical digestion.
Liver
Mouth – both chemical and mechanical digestion. Mechanical
because you chew your food, chemical because
Gall Bladder
your saliva contains amylase to break sugars
Esophagus – Transports your food from mouth to the stomach
only involved in mechanical digestion because it
squeezes the food.
Small Intestine
Stomach – Involved with both mechanical and chemical digestion
Mechanical because of the muscular churning and
squeezing of food; chemical because of the acids,
enzymes, etc. breaking food into smaller particles.
stomach
Pancreas
Large
Intestine
Small Intestine – Involved with chemical digestion because of the enzymes secreted by the pancreas
& compounds like bile from the liver go into the small intestine to break apart
larger molecules. This is the organ where most of the nutrient absorption takes
place.
Large Intestine – This is where water absorption takes place which would dehydrate the indigestible
parts left over and creates solid waste to be eliminated.
Liver – Produces bile which helps breakdown fats (chemical digest.) & is secreted into sm. intestine
Gall Bladder – stores biles before it is secreted into small intestine (chemical digestion)
Pancreas – secretes many different enzymes to break down fats, lipids, and proteins into the small
intestine (chemical digestion).
Enzymes
12. Draw and Label an enzyme and its substrate. Be sure to also label the active site.
13. Which macromolecule group do enzyme belong to? _______Proteins_______
14. Enzymes carry-out two different reactions in the human body. What are they and why are they
important?
A. Hydrolysis – water is used to break bonds of larger molecules to create smaller
ones, for example a polymer being broken into monomers. Important in
digestion.
B. Condensation/Dehydration Synthesis – water is created when two smaller
molecules are joined together to form a larger molecule. Important in growth.
15. Classify the following statements into one of the two reaction categories from above.
Building Muscle ____ Condensation/Dehydration Synthesis ________
Breaking Down Proteins _____ Hydrolysis ______
Weight Loss ______ Hydrolysis ________
Animals Storing Fat for Hibernation ______ Condensation/Dehydration Synthesis ____
16. What role(s) do enzymes play in digestion and metabolism? In other words, how do enzymes aid
digestion and metabolism?
Enzymes do both hydrolysis (breaking down reactions), and condensation or dehydration
synthesis (building up reactions) in the human body. Hydrolysis reactions occur in the
digestive system where food is being broken down into smaller units (polymers to monomers).
In this case, the enzyme binds to one larger substrate and breaks it into two smaller
substrates. Condensation or Dehydration synthesis reactions are important in growth,
replacing tissues like the skin, and building body structures. In this case, the enzyme joins two
smaller substrates into a larger one.
17. What is denaturation?
It is when the shape of an enzyme gets changed and the enzyme can no longer function as it
should because it cannot bind to the substrate.
18. How can an enzyme be denatured?
An enzyme can be denatured by being placed in acids or bases or subjected to heat