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Coursework

Hi Everyone,

Hope your ok, I wonder if you could help me please. For my AS coursework I have been asked to look at the rate of salivary amalyse on starch. From the experiment i added amylase to starch to each cuvette and timed the reaction and every 30 seconds i would add iodine to my first cuvette, then the second after another 30 seconds until each of my cuvettes had drops of iodine in them. Then, using a colorimeter a piece of equipment i've never used before i had to measure the abosrbancy. My results from the experiment i really poor. However, i was wondering is true to state that as time progresses the absorbancy numbers are going to ??decrease?? :confused:

as more light is going to pass through as theres less starch left from digesiton and so lighter iodine colour?

Also i can't think of any limitations of the experiment apart from the cuvettes.

I would truly appreciate any feedback before Sunday as this is really hard piece of work i need to get out of the way. Many thanks - take care,

Max007

Reply 1

Charli_90

Hm I did a different experiment but limitations could be lack of time to do sufficient repeats to get a good average? You could have used shorter time intervals between recordings? Smaller divisions (i.e. if you used a measuring cylinder on which the smallest divisions were cm3 where you could have used one that was accurate to 0.1 cm3 maybe?) on whatever apparatus you used to measure the volume of starch/ iodine solutions would have made it more accurate?