shake ó: unknown (general unknown) c. Add 3 drops of I KI solution to each test

Question

shake ó: unknown (general unknown) c. Add 3 drops of I KI solution to each test tube d. Record your observations and conclusions on e. Also,place a drop of 11KI solution on eachof the chart p the followicg: 1) a wedge of potato 2) a com kernel 3) a pea slice 4) a piece of white bread the observations and conclusions of part "e" on the chart provided below Is the starch localized in the corn and pea sceds? e # . Substance lested otser vations distilicH H2O glucose glycogen potato B. Lipids Sudan Dye Test Sudan dye (Sudan ) is a red dye that is absorbed by lipids, timing it a very bright red. Other solutions may mix with the dye, showing a pink color, but they do not actually combine with it and exhibit the bright red of a positive test. In other words, the Sudan dye is a lipid soluble dye. Materials Distilled water Sudan IV dye

Explanation / Answer

Test Tube Substances tested Color changes Conclusions 1 distilled water yellow No starch present. Control experiment. No color change. 2 glucose yellow Monosaccharides do not respond to iodine test. Therefore no color change. 3 sucrose yellow Disaccharides do not respond to iodine test. Therefore no color change 4 starch green Starch responds to iodine test. Should be giving a dark blue-black coloration. The active fraction of starch is starch amylose which is made up of a-D-glucose units. Iodine forms chains of I6 within the amylose helix, giving the coloration. The different color observed may be due to low concentration of the substance being tested. 5 glycogen red/brown Positive test for glycogen. Glycogen also forms helical coils like starch iodine complex, to which the iodine binds. But in contrast to the long and less branched helical coils of the starch-amylose, glycogen coils are more branched. That is why starch gives an intense blue-black coloration by binding more iodine, while glycogen gives a reddish brown coloration. 6 general unknown yellow/orange Non-starch substance. potato black Rich in starch. corn black Rich in starch. Starch localised in corn kernels pea black Rich in starch. Starch localised in pea seeds. bread black Rich in starch.

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.