Which of the statements about enzymes are true? Generally, an enzyme is specific for a particular substrate. For example, thrombin catalyzes the hydrolysis of the peptide bond between Arg and Gly.

A substrate must bind to the active site before catalysis can occur.

An enzyme yields a specific product, whereas a nonbiological catalyst may produce more than one product with the occurance of side reactions.

Catalysis occurs at the active site, which usually consists of a crevice on the surface of the enzyme.

Nonbiological catalysts and enzymes tend to have a similar degree of reaction specificity.

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

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acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.