Question

Biuret Violet Peptide Pink EXPERIMENTAL PROCEDURE: With a wax pencil, label and mark 3 clean test tubes at 2 cm and 4 cm. Fill as follows. Tube 1: Fill to the first mark with distilled water and to the second mark with biuret. Record any color change. Tube 2: Fill to the first mark with albumin solution and to the second mark with biuret. Record any color change. Tube 3: Fill to the first mark with starch solution and to the second mark with biuret. Record any color change. Color change Explanation Tube 1. water 2. albumin 3. starch : , Which of the 3 test tubes is the control sample? What is the definition of a control sample? Why do experimental procedures include controls?

Answer 1

Tube colour change Explanation 1 Water No colour change 2 Albumin purple or violet Blue Colour remained, as a indication that no interaction. Biuret reagent intescuts with peptide bond of protein and cut ions are reduled to cult and gives colour change Blue Colour remained, as a indication that no interaction between Starch and biuret reagent 3. Starch No colour change

1 . * Which of the 3 test tubes is the control Sample? Tube I containing distilled water and blueret reagent is considered as Control Sample. What is the definition of Control Sample ? - Control Samples are well known forensic Samples used to assure analyses are property pestor med so that results are reliable Why do experimental procedures include contools ? Experimental proudures include Controls to minimize the effects of Variables other than the Single independent Variable To increase reliability of the Gesults: To have a Comparision between control measure- ments and other measurements. * + *