Enzyme core practical Flashcards
what is the independent variable
Enzyme concentration (trypsin)
how do you vary the independent variable
Have 0.5%, 0.4%, 0.3% and 0.2% of trypsin
what is used as a control
distilled water in cuvette that you put in the colorimeter between each enzyme concentration
how do you measure the dependent variable
use a colorimeter calibrated to 440nm wavelength
what are the procedural variables and how are they controlled
volume of trypsin and milk used that were mixed together (2cm3 of each into cuvette)- control this by using a graduated pipette#
time between measurements- use a stopwatch to time 10 seconds between each transmission
wavelength of colorimeter- set it to 440nm
what are the environmental variables and how should they be controlled
age of milk - make sure milk is in date and has been stored correctly
temperature of trypsin and milk used in experiment- use a water bath set at 37 degrees to control temperature
what are the organism variables and how are they controlled
if an organism is used as source of enzyme then the age and mass of enzyme should be considered as a control
what repeats should be carried out
repeat practical 5 times for each concentration of trypsin used
calculate the mean average of results for an enzyme concentration to get one figure
how is this investigation made reliable
use the same volumes of solution in cuvette of milk and trypsin (2cm3 of each) measured by a graduated pipette
how is this investigation made valid
make sure you can get the same results if you were to attempt again
using the most accurate equipment to measure volumes of trypsin and milk (graduated pipette
conclusion that would be drawn from the results
as the enzyme concentration increases so does the rate of reaction
higher enzyme concentration mean there are more frequent collisions happening between the enzyme and the substrate meaning E-S complexes
if the enzyme concentration is too high then the reaction plateaus since the substrate becomes the limiting factor.
