Required Practical 1 Flashcards
(38 cards)
What must be constant in enzyme experiments?
pH.
Why equilibrate before a reaction?
To set the correct temperature.
What should you measure at the start and end of the reaction?
Temperature of the water bath.
Why check temperature changes during the reaction?
To see if temperature varied and impacted the reaction.
How can you keep the temperature stable?
Measure temperature and adjust with hot/cold water.
Why repeat experiments?
To get a more reliable average and detect anomalies.
What happens to molecules as temperature rises?
Molecules move faster (higher kinetic energy).
How does higher temperature affect enzyme activity?
More E-S complexes form as molecules collide more.
What happens above the optimum temperature?
The enzyme denatures.
What causes enzyme denaturation?
Breaking of hydrogen bonds.
What happens when the enzyme denatures?
The active site changes shape and no longer binds to the substrate.
Why is testing only 40°C invalid?
The optimum temperature could be between 31°C and 52°C.
How do you measure enzyme activity?
Use a colorimeter to measure absorbance.
What should you record while using a colorimeter?
The time to reach constant absorbance.
What factor affects enzyme activity related to the enzyme itself?
Enzyme concentration.
What factor affects enzyme activity related to the substrate?
Substrate concentration.
What environmental factor affects enzyme activity?
pH.
How do you ensure data is reliable?
Do at least 5 repeats and calculate the mean.
How do enzymes lower activation energy?
Induced fit changes the active site to form an E-S complex.
What factors can affect enzyme activity in an experiment?
Size of potato, Temperature, pH.
What’s the correct order for hydrogen peroxide concentrations?
0.33, 0.60, 0.86, 1.0, 1.0.
What should be plotted on the x-axis?
Hydrogen peroxide concentration.
What should be plotted on the y-axis?
Rate of reaction.
How should data points be plotted on a graph?
Accurately, with either point-to-point or a smooth curve.
