1. why is there no blue color with iodine when amylose reacts with saliva?

a. amylase in saliva causes the amylose chain to uncoil so iodine is not trapped.

b. amylase in saliva reacts with iodine causing it to be unable to complex with the amylose coil.

c. amylase in saliva causes the amylose chain to break into short chains and then into glucose which does not coil and so does not trap iodine.

d. amylase in saliva will replace the i2 in the amylose coil and so remove the color.

C

Explanation:

Iodine is used to test for starches. When iodine is placed in a solution with starch (non-reducing sugars) it turns blue-black color. When amylase, a starch, is mixed with saliva, it is ‘digested’ to glucose, a reducing sugar (the brown colour of the aqueous solution remains).  

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