Exercise 1. Put the necessary verb.

1. By this time tomorrow, I (finish) the project.

2. By 8 o'clock, the kids (fall) asleep.

3. By tomorrow morning, he (sleep) wonderfully.

4. By next year, she (receive) her promotion.

5. Robin (sell) his car by next Sunday.

6. Morgan (clean) the entire house by lunch.

7. We (dance) a few dances before midnight.

8. At this time tomorrow morning, they (begin) working.

9. At this time next week, we (catch) the thief.

10. At 2013, I (live) in Madrid for 5 years.

11. At 2020, they (work) here for 20 years.

12. By September, Julie (teach) us for over a year.

13. By October, I (study) English for 3 months.

14. At Monday, she (wait) for 2 weeks.

15. Before Saturday, you (do) all of your homework.

Exercise 2.Put the sentence from the text into Past Perfect, Future Perfect, Past Simple.

Fashion designers work in a number of ways in designing clothing and accessories.

Lesson 5 Metabolism of microorganisms

I. Topical vocabulary

II. Read the text

Metabolism of microorganisms

Microorganisms require food for energy and for growth. Food is required for energy for synthetic activities, for moving, and to maintain the living state. Food for growth is required to manufacture protoplasm. Microorganisms must have their food in solution in order for it to pass through their cell membranes. If they are not growing in a liquid medium, then the microorganisms will secrete extracellular enzymes that will liquefy their food.

Enzymes are organic substances that cause chemical reactions without being consumed in the reaction; therefore, they are called organic catalysts. They are produced by living cells and then become independent of the cells. They are incredibly active; e.g., one molecule of the yeast enzyme can catalyze the conversion of an inconceivably large number of sugar molecules into ethyl alcohol; and they are very specific, that is, they act upon only one substance. Extracellular enzymes are formed inside the cell and diffuse through the cell wall to cause their action. These enzymes bring about digestion in the human body and putrefaction (decomposition) in fruit, vegetables, and meat. Intracellular enzymes are formed in and remain within the cell.