Lab Exam IV Study Guide
Digestion
Review all factors that affect enzyme activity.
o Specificity
Each enzyme will catalyze only one reaction type
o Optimal conditions
Ex: Temperature, pH, substrate, solvent, concentration
Describe two ways enzyme activity can be measured in vitro.
o Disappearance of substrates
o Appearance of products
Memorize the information in the “Selected Enzymes of the Digestive System” table.
o Selected Enzymes of the Digestive System
Review the results of your experiments from this lab.
, test tubes that did not produce maltose. Then provide a specific explanation for why the chemical reaction did not occur for each
tube.
Test tube 1
o Chemical reaction did not occur because there was no enzyme (salivary amylase) present to catalyst the breakdown of the
substrate (starch).
Test tube 3
o Chemical reaction did not occur because wrong enzyme was present. (Pepsin breaks down proteins and not starch)
Test tube 4
o Chemical reaction did not occur because the boiling of the salivary amylase denatured the protein to begin with.
Test tube 5
o Chemical reaction did not occur because the 10 drops of HCl lowered the pH of the solution, thus, changing the optimal
environment for salivary amylase to work properly.
test tubes where the protein was not digested. Then provide a specific explanation for why the chemical reaction did not occur for
each tube.
Test tube 2
o Chemical reaction did not occur because the pepsin was denatured due to great increase in temperature.
Test tube 3
o Chemical reaction did not occur because the pH of the solution was 8 where as pepsin functions at a pH of 2. (denatured)
Test tube 4
o Chemical reaction did not occur because the solution was neutral and not acidic, thus, the pH of the solution was not the
optimal pH for pepsin. (denatured)
Test tube 6
o Chemical reaction did not occur because pepsin was not present.
Test tube 7
o Chemical reaction did not occur because amylase digests starch and not protein.
Test tube 8
o Chemical reaction did not occur because the temperature was too low for pepsin to function properly.
For each macromolecule, fill in the list below:
Carbohydrate
o Enzyme:
Salivary amylase
o Substrate:
Starch
o Substrate test:
Lugol’s Solution
o Product:
Digestion
Review all factors that affect enzyme activity.
o Specificity
Each enzyme will catalyze only one reaction type
o Optimal conditions
Ex: Temperature, pH, substrate, solvent, concentration
Describe two ways enzyme activity can be measured in vitro.
o Disappearance of substrates
o Appearance of products
Memorize the information in the “Selected Enzymes of the Digestive System” table.
o Selected Enzymes of the Digestive System
Review the results of your experiments from this lab.
, test tubes that did not produce maltose. Then provide a specific explanation for why the chemical reaction did not occur for each
tube.
Test tube 1
o Chemical reaction did not occur because there was no enzyme (salivary amylase) present to catalyst the breakdown of the
substrate (starch).
Test tube 3
o Chemical reaction did not occur because wrong enzyme was present. (Pepsin breaks down proteins and not starch)
Test tube 4
o Chemical reaction did not occur because the boiling of the salivary amylase denatured the protein to begin with.
Test tube 5
o Chemical reaction did not occur because the 10 drops of HCl lowered the pH of the solution, thus, changing the optimal
environment for salivary amylase to work properly.
test tubes where the protein was not digested. Then provide a specific explanation for why the chemical reaction did not occur for
each tube.
Test tube 2
o Chemical reaction did not occur because the pepsin was denatured due to great increase in temperature.
Test tube 3
o Chemical reaction did not occur because the pH of the solution was 8 where as pepsin functions at a pH of 2. (denatured)
Test tube 4
o Chemical reaction did not occur because the solution was neutral and not acidic, thus, the pH of the solution was not the
optimal pH for pepsin. (denatured)
Test tube 6
o Chemical reaction did not occur because pepsin was not present.
Test tube 7
o Chemical reaction did not occur because amylase digests starch and not protein.
Test tube 8
o Chemical reaction did not occur because the temperature was too low for pepsin to function properly.
For each macromolecule, fill in the list below:
Carbohydrate
o Enzyme:
Salivary amylase
o Substrate:
Starch
o Substrate test:
Lugol’s Solution
o Product:
