Scientists are studying compounds in a newly discovered rain forest plant. The plant produces an unusual substance that local people say acts as an anesthetic.

Question

What color change should the scientists look for when testing for carbohydrates?

Responses

dark blue to brown

purple to blue

blue to purple

brown to dark blue

Answer 1

When testing for carbohydrates, specifically with the use of Benedict's test for reducing sugars, scientists should look for a color change from blue to brick red. However, if they are using iodine to test for starch (a carbohydrate), the expected color change is from orange-brown to a dark blue/black.

Given the options you provided and focusing on the iodine test, the scientists should look for brown to dark blue when testing for carbohydrates like starch.