Biotechnology

Question 1

Genetic engineering in bacteria

Answer 1

bacteria are useful in biotechnology and genetic engineering due to their rapid reproduction rate and their ability to make complex molecules. Bacteria contains plasmids, circular rings of DNA, into which genes can be inserted, removed or changed. there are no ethical concerns over their manipulation and growth. and their genetic code is shared with all other organisms

Question 2

Role of anaerobic respiration in yeast during bread-making

Answer 2

• Yeast is a microorganism that can respire anaerobically (without oxygen) to release carbon dioxide.
• This can be used in bread-making, to make the dough rise as bubbles of carbon dioxide form.

Question 3

Role of anaerobic respiration in yeast during production of ethanol for biofuels

Answer 3

• Yeast is a microorganism that can respire anaerobically (without oxygen) to release carbon dioxide.
• Ethanol is also released during this reaction, which can be used to make biofuels that are used as an alternative to fossil fuels.

Question 4

The use of pectinase in fruit juice production

Answer 4

-Pectinase is an enzyme which is used in fruit juice production. Pectinase breaks down pectin, which is found in plants cell walls, and is used to hold the cell walls together. Adding pectinate therefore breaks down these cell walls to release contents of the cell, which increases the yield of fruit juice.

Question 5

The use of biological washing powders that contain enzymes

Answer 5

biological washing powders contains enzymes to break down different molecules. Amylase breaks down starch. lipase breaks down fats and oils, and protease breaks down proteins. The enzymes breaks these into smaller products that are water soluble, thus can be washed out easily. As enzymes denature at high temperatures and extreme pH, a lower washing temperature is needed, and the enzymes may not work in acidic or alkaline water.

Question 6

The use of lactase to produce lactose-free milk

Answer 6

Enzyme lactase can be used to produce lactose-free milk. When lactase is added to milk, it breaks down the lactose in glucose and galactose, which can be safely consumed by lactose-intolerant people.

Question 7

The role of the fungus Penicillium in the production of the antibiotic penicillin

Answer 7

• Penicillium is a fungus used to produce penicillin, an antibiotic.
• The fungus is placed in a fermenter to keep it at an optimum temperature and pH, so penicillin yield is high
• There is also an air inlet, so aerobic respiration can take place, and all other microorganisms are killed to limit contamination and competition.

Question 8

How fermenters are used in the production of penicillin

Answer 8

• The fungus is placed in a fermenter to keep it at an optimum temperature and pH, so penicillin yield is high
• Fermenters are usually made from a metal that will not corrode, such as stainless steel. Some have the capacity to hold thousands of litres.

Question 9

Genetic engineering

Answer 9

Changing the genetic material of an organism by removing, changing or inserting individual genes

Question 10

Genetic engineering using bacterial production of a human protein as an example

Answer 10

1. The gene which codes for the desired protein is located and isolated using restriction enzymes, forming sticky ends
2. The plasmid from the same bacterial cell is cut with the same restriction enzymes, forming complementary sticky ends to the isolated gene.
3. Inserting human DNA into bacterial plasmid DNA using DNA ligase (complementary sticky ends are joined using DNA ligase) to form a recombinant plasmid
4. This plasmid is inserted into bacteria, which will then produce this protein as the inserted gene is expressed.
5. Bacterial cell reproduces, making more cells which produce the protein.

Question 11

Examples of genetic engineering:

Answer 11

• Insulin Production: People with diabetes must take insulin to regulate their blood glucose concentrations. Genetic engineering allowed human insulin to be made in bacterial cells. This produces cheap human insulin, in high quantities.
• Herbicide and insect resistant plants: Genes can be inserted into plants to make them resistant to herbicides and insects. This means less crops die, so farmers have a larger crop yield.
• Vitamin-rich plants: Some plants can be genetically modified to increase number of vitamins in them. Beneficial to places that have food that lack vitamins. Genes can be inserted into crop plants to provide additional vitamins

Question 12

Advantages and Disadvantages of genetically modifying crops, such as soya, maize and rice

Answer 12

Advantages:

• Increases yield
• More nutritious (GM crops could be engineered to contain the nutrient that’s missing)
• Reduces costs
• Reduces need for pesticides.

Disadvantages:

• Loss of biodiversity
• Potential development of weeds that are resistant to herbicides
• GM crops are more expensive
• Long-term health impacts are unknown
• GM crops may contaminate wild species by crossbreeding