3 Part One. The Predicate

A Catalyst
A catalyst is a substance that alters the speed of a chemical reaction without itself undergoing any chemical changc, usually only a small quantity of it is required.

Catalysts are usually specific in action; thus, a catalyst for one reaction is more often than not useless for any other reaction. They are extremely important substances not only in the laboratory but also in chemical industry and in biological systems. Thus, the manufacture of sulphuric acid, ammonia and margarine involves the application of catalysts, the most of the chemical reactions that occur in our bodies are regulated by these substances. In biological systems substances called enzymes function as catalysts, c. g., specific enzymes are used to aid the digestion of food in the stomach.

Chemists have discovered the great majority o f reactions that procccd without catalysts. But there are almost innumerable other reactions that cannot be practically effected without a catalyst.

The phenomenon in which a relatively small amount of a foreign material, called a catalyst, augments the rate of a chemical reaction is called catalysis.

A catalyst provides the possibility of new elementary processes taking place, but it is not consumed during the reaction. If We cannot have it regenerated, there is no catalysis.
Mashq 3. Matnning asosiy tarkibini bir nechta jumlalarda ko'rsating.

Mashq 4. Matnning rejasini tuzing.

Mashq 5. Jumlalarni o'qing va matn tarkibiga mos kelishini ayting. Agar yo'q bo'lsa, ularni tuzating.

1. A catalyst is a substance that changes the rate of a chemical reaction.2. A catalyst undergoes little changcs in the reaction. 3. Catalysts are important both in laboratory and in industry. 4. Enzymes are catalysts for biological systems. 5. No reaction can procccd without a catalyst.

Mashq 6. Jumlalar matnida katalizatsiyaning fenomen sifatida ajratib turadigan xususiyatlarini toping va ularni rus tiliga tarjima qiling.