Biochemistry and the Environment

Question 1

What is Xenobiotics

Answer 1

refer to chemicals that are found in an organism that are not normally present there (ex: antibiotics)

Question 2

What are the concerns of xenobiotics

Answer 2

they often stay in the organism because they are unable to be metabolised or broken down further
- it gets into organisms through contaminated water and/or food

Question 3

Define biomagnification

Answer 3

the increase in the concentration of the pollutant as it moves up through the food chain

Question 4

Define bioaccumulation

Answer 4

the increase in the concentration of a pollutant in an organism as it absorbs or it ingests it from its environment

Question 5

Discuss problem of antibiotics in sewage treatments plants

Answer 5

• sewage treatment plant promote the spread of antibiotic resistance between bacteria
• contaminated water is consumed by animals
• they may cause cancer

Question 6

What is host-guest chemistry

Answer 6

involves the design, synthesis and investigation of simpler organic compounds that imitate the working features of naturally occurring compounds
- ex: enzymes

Question 7

Why is plastic bad for the environment

Answer 7

they are petroleum based and don’t degrade easily and cause pollution problems

Question 8

How to make biodegradable plastic

Answer 8

Adding starch to plastics makes them biodegradable

Question 9

How are biodegradable plastics broken down

Answer 9

Biodegradable plastics can be broken down in hydrolysis reactions due to the presence of ester and glycosidic linkage

Question 10

What are the products of starch-based plastics

Answer 10

carbon dioxide and water

Question 11

What are the advantages of biodegradable plastics

Answer 11

• starch is a renewable source
• increases the ability of microorganisms to break down the plastic
• reduces the amount of petrochemicals needed to make plastics
• reduces plastic waste

Question 12

What are the disadvantages of biodegradable plastics

Answer 12

• increases the use of fertilisers and pesticides
• plastic may degrade before use
• requires the use of land

Question 13

What is green chemistry

Answer 13

seeks to minimise the production and release to the environment of hazardous substances

Question 14

List some of the aims of green chemistry

Answer 14

• Reduce chemical waste of reactions
• increase in atom economy
• reduce the amount of toxic waste
• use more environmentally friendly solvents

Question 15

Outline importance of enzymes in green chemistry

Answer 15

• help in the dispersal and breakdown of oil spills and other industrial wastes
• in biological detergents can improve energy efficiency by enabling effective cleaning at lower temperatures

Question 16

Example of biomagnification

Answer 16

• DDT is an insecticide that was used to kill insects that spread malaria
• DDT is a soluble in fat and does not break down and accumulates in fatty tissues
• Taken in by microscopic plants eaten by small animals and then eaten by larger animals
• DDT got higher in concentration on the way up