F2022 Test's Most Missed Biochemistry Biology

11. The human pancreas is an organ that plays an important role in the process of digestion. The pancreas secretes (releases) trypsin. Trypsin is an enzyme that breaks down proteins. Which statement BEST describes what occurs to the enzyme trypsin AFTER it digests (breaks down) a protein?

• The trypsin molecule is not chemically altered by the reaction and may be used again.
• After binding to a protein molecule, the trypsin molecule is destroyed and must be replaced.
• After binding to the protein molecule, trypsin is converted to a lipid and used for energy storage.

26. Insulin, hemoglobin and enzymes are examples of which macromolecule group?

• carbohydrates
• lipids
• nucleic acids
• proteins

30. Where is energy stored in a macromolecule?

• in the wall
• in the bonds between atoms
• in the electron cloud
• in the cell

33. The picture shows carbon forming peptide bonds to make what biomolecule?

• proteins
• carbohydrates
• lipids
• nucleic acid

Bonus: The enzymatic hydrolysis, or breakdown, of sucrose by the enzyme sucrase will result in the formation of its two monosaccharide components, glucose, and fructose, as seen in the model above. The activity of an enzyme is affected by many factors including temperature and pH. Each enzyme has an optimum temperature and pH at which its reaction rate is the fastest. The optimum pH range for sucrase activity is 4 - 8. Imagine the pH of the environment in which the hydrolysis of sucrose is to occur has dropped to 2. How will this drop in pH influence point D in the model?

• There will be no change to the components of point D with a drop in pH; only temperature can denature the enzyme.
• More of the substrate (A) will fit into the active site (C), so more products will be produced.
• The enzyme (B) will allow less of the substrate (A) to move into the active site (C).
• The substrate (A) will no longer fit into the active site (C) because the enzyme has changed shape.