Amylase- Prac Assessment. (1 Viewer)

[burymeinblack]

Okay, so I've done the experiment but I still don't understand what I'm supposed to write about the reaction.

I feel so stupid but I just don't understand.

The potato covered in saliva turned black in extreme heat, slowly turned black in room temperature and did nothing in freezing water. I know this is a reaction to the iodine, because iodine is present in the starch solution. But, what has the starch got to do with the Amylase? Amylase breaks down starch.. But.. I'm so confused.. Wouldn't the starch be cooked out by the heat? So why did the hottest one turn black in the iodine solution?

Please help me!

 

[xiao1985]

if you heat it too much, yes, starch will be broken down by the heat...

the purpose of the question however, is for you to observe that at elevated temperature (at an optimal temperature infact), enzymes work best... anything away from that temperature, its activity start to die down...

 

[mzduxx2006]

Basically with the amylase experiment, what you are supposed to do is add iodine to the starch solution to turn it black, then the amylase is added and a colour reaction is supposed to be viewed, and the reaction rate is supposed to be timed. If you add more starch solution to make it more concentrated or more water to make it dilute, the reaction rate of the enzyme amylase will change, this futher supports the notion of substrate concentration effecting enzyme reaction rates. Similarly if you decrease or increase temperature the enzyme reaction rate will either speed up or slow down and if you increase the amount of acid or basic solutions [ie. adding hydrochloric acid or ammonia] it will affect the reaction rate of an enzyme. This is the purpose for adding the iodine [to view a colour change].

P.S --> it turned black in the iodine solution because the enzyme amylase has a faster reaction rate in slightly hotter temperatures.