A student mixed a 0.1% amylase solution with a 1% starch solution.
He performed a number of food tests on the mixture immediately after mixing and obtained the following results :
Iodine test +
Albustix paper test +
Benedict's test -
If he repeated the food tests on the mixture 10 minutes later, what would be the possible results?
Iodine test Albustix paper test Benedict's test
A + + -
B. - + -
C - - +
D + - -
key: + positive result
- negative result
Thats my question(:
thanks
BIO mc question(:
2008-03-24 3:23 am
回答 (2)
2008-03-24 4:55 am
✔ 最佳答案
First of all, albustix test must be positive since protein is not used up in the reaction.Therefore, C or D must not be the answer.
Owing to the fact that the time carrying out the experiment is too short, only some of the starch in the mixture is broken down as maltose.
besides, as I have mentioned, the time required to turn the starch into maltose is quite long. The benedict's test cannot give a positive result because not so much maltose is formed.
參考: original
2008-03-24 3:37 am
the answer is C - - +
the enzyme needs time to convert starch to reducing sugar.
so the test at the beginning shows negative result for benedict's
test.
so after 10 minutes, positive result appears.
the enzyme needs time to convert starch to reducing sugar.
so the test at the beginning shows negative result for benedict's
test.
so after 10 minutes, positive result appears.
收錄日期: 2021-04-29 20:24:22
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