RP5 Ph effect on amalyse Flashcards
Risk assessment
Safety goggles
Care with hot water
Step 1
Place one drop of iodine solution into each well of a spotting tile
Step 2
Take 3 test tubes - label each one
what do you label and add to each test tube
1st test tube = add 2cm cubed of starch solution
2nd test tube = add 2cm cubed of amylase solution
3rd test tube = add 2cm cubed of PH5 buffer solution
Buffer solution - used to control PH
Step 4
Place all 3 test tubes in water bath at 30 degrees
Step 5
Leave them for 10 minutes - to allow solutions to reach right temperature
Step 6
Combine 3 solutions into one test tube
Mix with a stirring rod
Step 7
Return test tubes to water bath and start stop watch
Step 8
After 30 seconds use the stirring rod to transfer one drop of solution to a well in the spotting tile that contains iodine
describe a positive result ( if starch is present)
The iodine should turn blue - black if starch is present
what does amalyse do
amalyse breaks down starch into glucose
how do we know when the reaction is complete
when the iodine solution stays orange
why does the iodine solution stay orange
iodine turns changes colour in presence of starch
but amalyse has broken down starch into glucose while combined in test tube
so iodine no longer changes coulor
how long do we repeat/ take a sample and put in iodine solution
every 30 secs till iodine solution stays orange
What does it mean when iodine remains orange?
When iodine remains orange - tells us that starch is no longer present and the reaction has been completed
