AP Bio FRQ #2
January 22nd, 2013
A.) Graph #1
A.) Calculation
The rate of reaction from 0-30 minutes is 0.34667; r=10.4μM /30 minutes
B.) Explanation
The reaction was observed after 30 minutes because the reaction rate eventually slows down and the enzyme reaches its maximum potential. Since the enzyme is using the substrate so quickly, the substrates concentration depletes. That means the rate will slow down. Our graph shows that after about 40 minutes, the enzyme is less active.
C.) Graph #2
C.) Explanation
The substrate is consumed faster since there is twice as much enzyme. The starch would have broken down the substrate fastest in the first ten minutes, which is why the graph’s 2nd point is double. But it still levels out at the same time and the concentration of the maltose is consistent with the original because no extra starch was used. However, since the rate of reaction is being doubled as well, that means the maltose would level off much quicker than the original.
D.) Two Environmental Factors
One important factor that can affect the rate of enzyme-meditated reaction would be temperature. Below 5° the enzyme is inactive. When they enzyme is cold, molecules move slower, and the substrate an enzyme don’t really work. From 5° to 40°C the enzyme increases in activity, but then denatures at 40°C. If you heat the enzyme above its optimal range, the hydrogen bonds break meaning the protein loses it secondary and tertiary structure. The denaturing causes the active sight to change shape and the substrate no longer fits. That means the rate of reaction decreases, and the enzyme can no longer regain its shape unless with a chaperonin.
The second important factor is pH level. The pH level affects the state of ionization of the enzyme. If the enzyme pH is too low or too high, it can cause it to denature. This decreases the enzymes activity and rate of reaction. Most enzymes have an optimum pH at neutral, but it is