the effect of a variable on the rate of reaction. Flashcards
What variables affect the enzymes?
= enzyme concentration
= substrate concentration
= temoerature
= ph
= inhbitor
=the aim is to determine the effeft of ph on the enzye trypsin the identify the optimum ph
What is the method:?
= use forceps to place a peice of dilm, in the slit cut into the straw
= use the syringe to measure 4cm^2 of trypsin, into a est tube
= use a duffernt syringe to measure4cm^3 of the ph4 buffer solution and place into the same test tube
= place the test tube in a beaker of water at 37 degrees using a therometer
= wait 5 minutes for the contents of the test tube to reach 37 degrees
=
= we repeat the experiment with the different ph levels
What do we do after using the water bath?
= once at temperature place the straw with film attached into the test tube
= and start the stop clock immediatley
= dunk the straw in and out of the soltuion every 10 seconds, to look at the film
= when the film becomes completly clear, the reaction has finished compare the film to an already clear film to decide end point
= record the time this took
= some ph the enzyme may eb denatured, so none of the gelatin is digested
= if there is no change after25 minutes, then stop and record no reaction
= repeat for different oh
How can we do a control variable?
= repeat using water instead of trypsin, as a control experiment
what would the graph look like?
= x axis is PH
= y axis is mean rate of reaction
= u cannot make a conclusion on the optimum ph however, as this may be in an intermediate
what are the limitations of the method?
= the end point is subjective- leads to innacurate time measurements
= water bath was not thermostatically controlled, therefore temperature decreaes
= not enough ph intermediate ranges to accurately identifyf the ph ramge
= the range of the tested ph values was not wide enoughb as the poijt,at whih trypsin denatures was not identiied
