testing foods Flashcards
How would a student test for protein
Grind food up, add biuret solution, turns purple/lilac if present
How would a student test for starch
Add iodine solution to sample, solution will turn black/ blue if present
How would a student test for sugar
Grind sample up, mix with water, add benedict solution, and place in hot water bath, if solution is present it will turn red
Why is ethanol used in the extraction of cells
to preciptiate the DNA
How does a calorimeter work
Small samples of material are placed in the machine which burns them. The energy given off when the material burns is measured.
Why is salt water used when crushing food in DNA extraction
Breaks apart cells from each other and break downs cell walls, DNA clumps together due to salt
Why is detergent added in DNA extraction
Ruptures cell membrane
Why is protease added in DNA extraction
Uncoils DNA