Homework

8. Study the vocabulary to the text “Photosynthesis”:

carbohydrate	[ֽka:bə'haıdreıt]	углевод
chemical	['kemık(ə)|]	химикаты, химический
convert	['knvə:t]	преобразовывать, превращать
cultivate	['kltıveıt]	культивировать, выращивать
equation	[ı'kweın]	уравнение
fat	[fæt]	жир
food chains	[fu:d t∫eın]	пищевые цепи
hydrogen	['haıdrədən]	водород
oxygen	['ks ı dən]	кислород
mesophyll	['mezəfaıl]	мезофилл
phloem	['fləuəm]	флоэма
producer	[prə'dju:sə]	продуцент
protein	['prəutı:n]	белок
resistant	[rı'zıst(ə)nt]	сопротивляющийся, стойкий
respiration	[ֽrespə'reı∫(ə)n]	дыхание
sucrose	['su:krəus]	сахароза
spongy	['spndı]	губчатый
temperature drop	['temprıtə drp]	перепад температуры
vessel	['vesl]	сосуд
waste product	[weıst 'prd kt ]	побочный продукт

9. Read and translate the text “Photosynthesis”, find in the text:

a) sentences in Present Simple Active;

b) sentences in Present Simple Passive.

Photosynthesis

Kate is a student at last! Every day she realizes this deeper and deeper. Her life changes greatly. Everything is new: new people, new teachers, new subjects, new dreams, and new friends. Each day is different from the previous one! So many new impressions! Every day Kate wakes up at 7 o` clock, takes a shower, has breakfast and after that goes to the university. Her favorite subject is botany, she dreams of becoming a good specialist in sphere of selection. In future she wants to cultivate new sorts of plants resistant to temperature drops in the region of the North West. That’s why she must learn all the processes taking place inside of plants. Kate’s group usually has three hours of botany three times a week. They listen to lectures, write tests, and have seminars. Today they are having a lecture about one of the most important processes, essential for the life on the earth. It is Photosynthesis. Below is the fragment of Kate’s lecture. Read it and try to separate facts that are familiar for you from those which are completely new.

Green plants are at the beginning of all food chains. Plants are known as ‘producers’ because only plants make their own food by building up carbohydrates, proteins and fats from simple inorganic chemicals. Green plants need sunlight to produce food. They ‘capture’ the sunlight energy using the chlorophyll in their leaves and use it to make a sugar called glucose, which is either used in respiration or converted into starch and stored.

Photosynthesis is the chemical change which happens in the leaves of green plants. It is the first step towards making food not just for plants, but ultimately for every animal on the planet as well. During this reaction, carbon dioxide and water are converted into glucose and oxygen. The reaction requires energy in the form of sunlight, and chlorophyll must also be present.

The glucose produced in the photosynthesis reaction can be converted to sucrose and carried to other parts of the plant in phloem vessels. Glucose can also be converted into starch and stored (the starch can later be turned back into glucose and used in respiration). Oxygen is a ‘waste’ product of photosynthesis.

Photosynthesis takes place in the mesophyll cells inside a green plant’s leaves.

As you can see there are two kinds of mesophyll cells – palisade mesophyll and spongy mesophyll. The mesophyll cells contain tiny bodies called chloroplasts which contain green chemical called chlorophyll. Chlorophyll enables the light energy from sunlight to be converted into chemical energy for the photosynthesis reaction.