A Benedict’s solution = blue; iodine solution = blue-black
B Benedict’s solution = blue; iodine solution = brown
C Benedict’s solution = brick red; iodine solution = blue-black
D Benedict’s solution = brick red; iodine solution = brown
A human cell contains a length of DNA that carries the code for making which substance?
A student set up a test-tube containing starch, water and amylase.
How could the student test whether the amylase had digested all the starch?
A Add Biuret solution.
B Add dilute hydrochloric acid.
C Add iodine solution.
D Weigh the test-tubes and contents before and after the experiment.
When solution X is tested with iodine solution, a blue-black colour is observed.
A different solution, Y, is added to a new sample of solution X and the mixture is shaken and left for 30 minutes at 40 °C. When tested with iodine solution, an orange-brown colour is observed.
What are solutions X and Y?
A X = maltose; Y = amylase
B X = maltose; Y = lipase
C X = starch; Y = amylase
D X = starch; Y = lipase
Which row correctly identifies the chemical elements found in proteins?
Four foods were tested for:
* fat (using ethanol),
* protein (using the biuret test),
* reducing sugar (using Benedict’s solution),
* starch (using iodine solution).
Which food contains protein and starch?