Учебно-методическое пособие по английскому языку для вузов. Кислякова Н.В - 17 стр.

                                       UNIT 6

Pre-reading activities
I. Match the following Russian words with their English equivalents:

алкалоиды из семейства пасленовых                     hydrogen
водород                                               nitrogenous
азотное                                               flowering plants
углерод                                                unstable glycosides
нестойкие гликозиды                                    solanaceous alkaloids
цветоносные растения                                  carbon


II. Find the meaning of the following words and word combinations in a
dictionary and give Russian equivalents to them.
1. vegetable origin
2. crystalline
3. liquid
4. rare
5. slightly
6. organic solvent
7. dilute
8. ring-shaped molecule
9. serve
10. support


Reading
III. Read and translate the text.



                            Alkaloids and Carbohydrates

   Alkaloids are basic nitrogenous compounds of vegetable origin. They possess
some marked physiological action. Most alkaloids are crystalline substances and
contain carbon, hydrogen, and oxygen in their molecules, but some of them are
liquids and oxygen free. Coloured alkaloids are rare. Alkaloids occur in many
families of flowering plants in the form of salts of organic acids or associated with
tannins. The pure alkaloids are usually present in the fresh plant as unstable
glycosides. Some solanaceous alkaloids occur in glycosidal combination with
sugars. The free bases are slightly soluble in water, аlcohol, organic solvents and
their salts, but readily soluble in dilute acids with the formation of alkaloidal salts.
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