(10 points) Certain color reactions are often used in biology to identify certain chemical compositions...

Diuret

Purple

(2)Methyl green? Pyrrole red

(3)Kenna green

Blue-green

(4)Bromo muscovado phenol blue

Potassium dichromate

Gray-green

Answer AnalysisTest Question Analysis: Identification of compounds in biological tissues:(1)Ferrin's reagent can be used to identify reducing sugars.The color change of the solution under the condition of heating in a water bath is a brick-red ( precipitate). Ferrin's reagent can only test biological tissues of reducing sugars (such as glucose, maltose, fructose) presence or absence, and can not identify non-reducing sugars (such as starch). (2) Proteins can have a purple color reaction with urea reagent. (3) Fats can be identified by Sudan III stain (or Sudan IV stain), which is orange (or red).

Observation of the distribution of DNA and RNA in the cell is the principle of the experiment: methyl green and pyrrole red two kinds of stains on the affinity of DNA and RNA is different, the use of methyl green and pyrrole red mixture of staining on the cell staining, and at the same time to show that the distribution of DNA and RNA in the cell, the results of the observation of the nucleus was green, the cytoplasm was red, indicating that the DNA is distributed in the nucleus, RNA to be distributed in the cytoplasm. RNA should be distributed in the cytoplasm. Kenna green is a living cell dye that specifically stains mitochondria, and can stain mitochondria blue.

The mitochondria are colorless rods, globules, etc., stained blue-green with Kinetochrome green and then prepared for observation.

To detect the production of CO2: to make clarified lime water turbid, or to make aqueous bromo-muscovite phenol blue solution from blue to green and then yellow; to detect the production of alcohol: orange solution of potassium dichromate, under acidic conditions and alcohol reacts and turns gray-green.

Examination point: this question comprehensive examination of the textbook related to the relevant knowledge of the experiment, intended to test the students to understand the main points of the knowledge gained, analytical ability and the ability to analyze the problem of the comprehensive use of knowledge gained.