Investigating Enzymatic Reactions Flashcards
(13 cards)
Which enzyme breaks down starch and what does starch become when it is broken down?
The enzyme is called ‘amylase’ and starch becomes ‘maltose’ when it is broken down.
What chemical can you use to detect starch and what colour will it turn if starch is present?
The chemical is ‘iodine’ and if starch is present then the solution will go from a browny-orange to a ‘blue-black’.
What is the first step in the pH experiment?
Put a drop of iodine solution into every well in a ‘spotting tile’
What is the second step (aka the set up) of the pH experiment?
Place a ‘bunsen burner’ on a ‘heat proof mat’ and a ‘tripod’ and ‘gauze’ over the bunsen burner.
Put a ‘beaker’ of water on top of the tripod and heat the water until it is ‘35 degrees celsius’.
What is important about the temperature that the water is being heated to?
It must stay consistent throughout the experiment.
What is an alternative to a bunsen burner if you don’t have one? What other reason might there be for someone else to not use a bunsen burner?
You could use an ‘electric water bath’ to give you more control over the temperature.
What is the third stage of the pH experiment?
Use a ‘syringe’ to add 1cm^3 of ‘amylase solution’ and 1cm^3 of a ‘buffer solution’ with a pH level of 5 to a ‘boiling tube’.
Using ‘test tube holders’ put the tube into the beaker and wait for 5 minutes.
What is the 4th and 5th step of the pH experiment?
- Use a different syringe to add 5cm^3 of starch solution to the ‘boiling tube’.
- Immediately mix the contents of the boiling tube and start the stop watch.
What is the 6th step of the pH experiment?
Use ‘continuous sampling’ to record how long it takes for the amylase to break down the starch. To do this, take a fresh sample with a ‘pipette’ every ‘30 seconds’ and drop it into a ‘well’. When all of the starch is broken down, the solution in the ‘well’ will remain a ‘browny-orange’.
What do you control measurably when repeating the pH experiment?
You increase the pH level.
What is the dependant, independent and any other variables in the pH experiment?
Dependant - how long it takes the starch to break down
Independent - the different pH values
Others - concentration, volume of amylase, volume of starch, etc
What formula is used to calculate the ‘rate of a reaction’ and what unit is used?
Formula: Rate = 1000/time
Unit: S^-1
What os the formula for the ‘rate of a reaction’ if the change is what’s measured?
Formula: rate = change/time
