Enzymes RP - Chat GPT Flashcards
(13 cards)
What is the purpose of Required Practical 5?
To investigate the effect of pH on the rate of reaction of the amylase enzyme.
What is the background to this practical?
The experiment investigates how changes in pH affect the rate of enzyme activity. Amylase is an enzyme that breaks down starch into sugars and is made in the salivary glands and pancreas.
What is pH?
pH measures how acidic or alkaline a substance is (1 = strong acid, 7 = neutral, 14 = strong alkali).
How do you conduct the experiment?
Put test tubes of amylase and starch in a water bath until they are the same temperature. Add amylase to starch, remove a drop every 30 seconds, and add it to a spotting tile with iodine solution. Record how long it takes for starch to be completely digested.
What do you use to test for the presence of starch?
Iodine solution is used to test for starch presence.
What does it mean if the iodine solution changes to blue/black?
It indicates that starch is still present, meaning it hasn’t been fully digested.
What does it mean if the iodine solution stays orange/brown?
It indicates that the starch has been completely digested by the enzyme.
What is the independent variable (IV) in this experiment?
The pH, which is changed using different buffer solutions.
What is the dependent variable (DV) in this experiment?
The time taken for amylase to digest starch, measured by using iodine solution to check for starch.
What are control variables (CVs) in this experiment?
Temperature, concentration of amylase, and starting concentration of starch.
How can the experiment be modified?
The experiment could be modified to investigate the effect of a different variable, such as temperature, while keeping pH constant using a buffer.
What safety precautions should be taken during this experiment?
Iodine/enzyme solution could irritate skin, and pH buffer solutions could be corrosive. Wear eye protection, take care with chemicals, and wash off skin immediately if exposed.
What does a blue/black colour on the spotting tile indicate?
It indicates the presence of starch, meaning it has not been fully digested.
