G10 Unit 28 Catalyzed Reactions in the Environment

Question 1

part of the enzyme molecule where the reaction happens. Enzymes may have one or multiple of these

Answer 1

active site

Question 2

There are different enzymes that catalyze the reactions of different molecules.

Question 3

molecules perfectly fit to the active site of the enzyme like a jigsaw puzzle

Answer 3

substrates

Question 4

Process enzyme

Answer 4

Substrate
Enzyme substrate complex
Enzyme product complex
Product

Question 5

Substrates are the ones that the enzymes will act on, thus making them the equivalents of reactants in a non-biological chemical reaction.

Furthermore, enzymes are usually specific to substrates.

Question 6

In humans, enzymes are involved with all the body systems. Some examples of these are the following:

Amylase, found in saliva. Used for breaking down starch.

Trypsin and chymotrypsin, produced by the pancreas. These are examples of proteases, which break down proteins.

Several lipases, for emulsifying fats in the digestive system.

DNA polymerase, which aids in DNA replication.

Helicases, for unwinding DNA strands.

Question 7

can also be observed in the atmosphere, particularly in the ozone layer.

Answer 7

Catalysis

Question 8

_ _ in the stratosphere protects organisms from ultraviolet rays coming from the Sun

Answer 8

ozone layer

Question 9

a molecular form of oxygen where each molecule has three oxygen atoms,O3O3, instead of the usual two,O2O2

Answer 9

Ozone

Question 10

The sun emits ultraviolet rays as part of the spectrum of light that it emits.

The ozone layer absorbs these ultraviolet rays from the sun and prevents excessive amounts of radiation from reaching the Earth’s surface.

Question 11

Different chemical reactions are involved with the balance of oxygen and ozone in the atmosphere:

When oxygen absorbs ultraviolet radiation with wavelength less than 240 nm, it splits into two free oxygen atoms.

When a free oxygen atom encounters an oxygen molecule, it forms ozone molecules.

When ozone absorbs ultraviolet radiation greater than 240 nm, it splits into an oxygen molecule and free oxygen atom.

Question 12

were developed and have become useful in products such as hair spray and as cooling agents in refrigerators.

Answer 12

chlorofluorocarbons

Question 13

A class of chemicals calledchlorofluorocarbons(CFCs) were developed and have become useful in products such as hair spray and as cooling agents in refrigerators.

When released in the atmosphere and exposed to ultraviolet radiation, the chlorine atoms in CFCs are released.

The presence of these chlorine atoms serve as catalysts of the decomposition of ozone to oxygen, which naturally decreases the amount of ozone in the atmosphere and shifts the balance towards oxygen.

Question 14

Ultraviolet light in the right amount is actually beneficial to the environment.

However, many biological and environmental processes are negatively impacted by the absorption of excessive amounts of ultraviolet light. Some of these include:

Premature skin aging and skin cancer for humans and some other animals.

Damage to DNA.

Damage to some organs, like the eyes.

Can suppress immune response.

Can suppress plant growth.

Has an effect on the food chain, particularly on the efficiency of producers.

Can affect the abiotic (nonbiological) factors of the environment.