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What type of food will give a negative Iodine test and a positive Biuret Solution test?
Wiki User
∙ 11y ago
An iodine test is used to test for the presence of starch (or polysaccharides, specifically amylose
or amylopectin).
A Biuret
solution test is used as an indicator for peptide bonds within proteins. Therefore, if you get a negative iodine test and a positive Biuret
test, you would probably be testing a animal food source (beef, chicken, pork). Overall, any food that doesn't have starch present within it would be appropriate to use.
Hope this helps!
Wiki User
∙ 11y ago
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Why did a solution of saliva and oats test positive with benedict's test and iodine test if the oats alone tested positive only in the iodine test and the saliva alone was negative for both?
polysaccharides and simple sugar
What substance is used to test for starch?
The presence of starch can be tested with the help of Iodine. Similarly Benedict's test solution is also used to detect the presence of starch.
What indicators are used for each molecule simple sugars starches lipids proteins?
simple sugars- benedicts starches- iodine protein- biuret lipid- brown paper bag test
Iodine and Benedict's solution were both used to test for certain nutrients in a sample of food If both tests were positive for the nutrients the sample must contain?
polysaccharides and simple sugar. Hope that helped :)
What is the chemical test to confirm the presence of starch?
1. Place a small amount of starch powder in a test tube filled with cold water 2. Boil it to make a clear solution 3. Once the solution has cooled off, you should put 3 or 4 drops of iodine solution in it. 4. The solution should turn dark blue.
Why would a negative iodine test for starch indicate a positive result for the enzymatic degradation of starch by amylase?
Perhaps the iodine solution was old and gave a false negative.
Why did a solution of saliva and oats test positive with benedict's test and iodine test if the oats alone tested positive only in the iodine test and the saliva alone was negative for both?
polysaccharides and simple sugar
What is the chemical indicator used to test protein?
To test for protein. Biuret or solutions of sodium hydroxide and copper sulfate. Tested with a dropper a + result will be purple or something
How would you test an unknown solution for each of the following sugar fat starch protein?
Sugars - Benedict's solution Fats - Brown Paper Starch - Iodine Protein - Biuret Solution
What substance is used to test for starch?
The presence of starch can be tested with the help of Iodine. Similarly Benedict's test solution is also used to detect the presence of starch.
What color is gram negative stain and gram positive stain if you forget to apply iodine?
If iodine is not applied, both the gram-positive and gram-negative stains will appear to be gram-negative. The iodine acts as a mordant that helps to fix the crystal violet stain in the gram-positive bacteria, making them appear purple. Without iodine, the crystal violet stain can be easily washed out of both gram-positive and gram-negative bacteria, resulting in a pink or red color.
Is iodine a positive or negative charge?
No, nitrogen is more electronegative than iodine. Electronegativity of nitrogen= 3.04 Electronegativity of Iodine = 2.66
What solution is use to test starch?
Iodine-KI reagent. Add to the substance being tested directly. Result: If positive, Turns Blue/Black If negative, (absence of starch) Solution remains orange/yellow.
Would the iodine solution change colour when it is tested on a slice of bread?
negative
What does lugol's iodine?
it is iodine and potassium iodide solution It's a orange colored solution that consists of Iodine and Potassium Iodide and is used to test a substance for starch. If the color of the solution turns black when put on/in the substance, then the substance is positive for starch.
What is a positive result for the Biuret test?
positive result for when buiret is added to protein is blue or violet/pale lilac colour. (not pink). positive result for when iodine is added to starch is blue or black colour (not pink).
Why do you use iodine to stain a cell?
Iodine stains starch contained in cells. Iodine is also used to distinguish between Gram negative and Gram positive bacteria. The Gram stain contains iodine.
