biology tests

test for glucose & other reducing sugars

(pale blue) benedict’s solution and heat to 95°C

what colour will benedict’s turn in presence of glucose

high amount → orange-red colour

low amount → yellow/green

test for starch

brown iodine solution mixed with food

what colour will iodine turn in presence of starch

brown → blue/black

test for protein

add pale blue biuret reagent (copper sulfate and sodium hydroxide)

what colour does biuret reagent turn in presence of protein

pale blue → purple

test for fat

add a few drops of ethanol, shake the test tube and leave for one minute, then pour the solution into a test tube of water

what colour do fats change after the ethanol test

milky-white/ cloudy