biotechnology

Question 1

discuss why bacteria are useful in biotechnology and genetic modification

Answer 1

• few ethical concerns over their manipulation and growth
• presence of plasmids (easy to transfer from one cell to another)
  can be used to move genes from one organisms cell to another.
• rapid reproduction rate (able to make huge range of diff chemical substances)
• ability to make complex molecules

Question 2

Describe the role of anaerobic respiration in yeast during the production of ethanol for biofuels

Answer 2

• Used to produce ethanol
• Anaerobic respiration in yeast turns sugar and other nutrients to alcohol
• Alcohol distilled to make pure ethanol

Question 3

Describe the role of anaerobic respiration in yeast
during bread-making

Answer 3

• Yeast mixed into bread mixture
• In warm environment yeast ferments sugar
• Anaerobic respiration produces CO2 bubbles
• Bubbles make dough rise

Question 4

Describe the use of pectinase in fruit juice
production

Answer 4

• pectin is a carbohydrate found in plant cell walls
• pectinase is an enzyme that breaks down pectin; it’s produced by bacteria and fungi to speed up fruit/veg decomposition.
• fruit juice manufacturers use pectinase to help break down cell walls in the fruit so juice can be extracted more easily.

Question 5

Explain the use of lactase to produce lactose-free
milk

Answer 5

• some ppl can’t digest lactose bc they don’t produce enzyme lactase
• lactase breaks down lactose into glucose and galactose
• can be used to make lactose-free milk
• to make the milk, lactose is immbolized - usually by encasing it in alginate beads.
• milk is passed over the beads and lactose is broken down.

Question 6

Describe how fermenters can be used for the large-scale production of useful products by bacteria and fungi

Answer 6

Microorganisms such as bacteria and fungi
* can be grown on a huge scale inside an industrial fermenter
* products they make can be collected and processed for a variety of applications

Fusarium
fungus used to grow meat-substitute mycoprotein

Penicillium
fungus used to produce antibiotic penicillin

Insulin
genetically modified bacteria can be grown to produce insulin to treat diabetes.

Question 7

Describe and explain the conditions that need to be controlled in a fermenter

Answer 7

Temperature
* optimum temp for enzymes in microorganisms to work effectively
* adjusted by pouring cold water/hot water/steam

pH
* measured using a probe
* co2 produced lowers pH. adjusted by adding small quantities of acidic/alkaline liquids

Oxygen
* if microorganism repires aerobicaly, air is bubbled through contents of fermenter; this provides oxygen
* fermenter has outlets through which waste gases can escape to make sure pressure inside fermenter doesn’t build up

nutrient supply
* water n nutrients needed for growth added to fermenter

waste products
* constantly removed to prevent toxic substance building up
* can kill microorganisms