biotechnology and genetic modification (topic 21)

Question 1

why are bacteria useful in biotechnology and genetic modification

Answer 1

due to their rapid reproduction rate and their ability to make complex molecules
few ethical concerns over their manipulation
and growth
the presence of plasmids

Question 2

biotechnology

Answer 2

The exploitation of biological processes by humans for industrial and other purposes. eg. use of bacteria in production of yogurt, yeast in production of bread

Question 3

genetic engineering

Answer 3

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

Question 4

how are plasmids involved in genetic engineering

Answer 4

bacterial cells contain plasmids, which is a circle of dna, plasmids naturally pass from one bacteria to the other, in genetic modification a gene from a protein can be inserted into a plasmid, this gene will then be transferred to the genetic material of a bacterial cell, which then expresses the gene making required protein.

Question 5

what is yeast

Answer 5

A microscopic single-celled fungus that is used in bread and beer making processes.
Yeast cells obtain their energy by anaerobic respiration

Question 6

anaerobic respiration

Answer 6

chemical reactions in cells that break down nutrient molecules to release energy without using oxygen.

Question 7

word equation of anaerobic respiration in yeast

Answer 7

glucose → alcohol + carbon dioxide

Question 8

symbol equation for anaerboci respiration in yeast

Answer 8

C6 H12O6 → 2C2H5OH + 2CO2

Question 9

fermentation

Answer 9

A metabolic process involving the conversion of carbohydrates to alcohol, often using yeast.

Question 10

why is yeast used to make bread

Answer 10

because it releases carbon dioxide, making bread rise, ethanol released/ produced is boiled away when bread is cooked

Question 11

why is yeast used to make alchol/ biofuels

Answer 11

beccause it releases alchol

Question 12

how is yeast used to produce biofuels

Answer 12

the alchol produced by yeast in anerobic respiration is called ethanol, sugars from plants are the raw materials for this process or cellulose from plant cell walls (sugars are mixed with yeast and water, and kept warm in an oxygen-free atmosphere)

Question 13

explain process of producing ethanol with yeast

Answer 13

1- biomass is harvested and delivered
2- biomass cut into shreds, pre treated, with heat and chemicals to make cellulose accesible for the enzymes
3-enzymes breaks down cellulose chains into sugars
4- yeast ferments sugar into ethanol
5- ethanol is purified through distillation

Question 14

what are ways in which enzymes are used in industries

Answer 14

the production of fruit juice
biological washing powders.
production of lactase free milk

Question 15

what enzyme is used in fruit juice production

Answer 15

pectinase

Question 16

how and why is pectinase used in fruit juice production

Answer 16

Pectin is a protein that holds cell walls together. Pectinase then breaks down the pectin molecules, so that the cell walls fall apart and opening up the cells so allowing juice to be extracted more easily, also makes juice more clear.

Question 17

how and why are enzymes used in biological washing powders

Answer 17

contain enzymes to digest (break down) the substances in fabric stains
eg protease removes blood protein- amino acids
lipase removes fats- glycerol and fatty acids
amalyse removes starch- simple sugars

Question 18

why is lactose intolerance caused

Answer 18

lacking lactase in the body (enzymes produced in walls of intestine digests lactose to form two simpler sugars, glucose and galactose, which are quickly absorbed into the bloodstream for use in respiration)

Question 19

what is used to produce lactose free milk

Answer 19

lactase

Question 20

how is lactose free milk produced

Answer 20

milk is passed through a mesh that contains the immobilised enzyme of alginate beads for several cycles until no more lactose is detected

Question 21

what is the difference in lactose free milk

Answer 21

as lactase breaks down lactose- glucose, the milk contains more sugars and thus is sweeter

Question 22

what is a fermenter

Answer 22

designed to optimize the growth of a microorganism such as bacteria usually maid of stainless steel.

Question 23

what are the structures found in a fermenter

Answer 23

stirrer- Keeps the microorganisms, nutrients and temperature evenly distributed

nutrients and microogransims in- such as glucose and protein, are provided for the growth of organism

Sterile air supply- Provides oxygen for the microorganism. Air is sterilised to prevent contamination of mixture by unwanted microorganism

temp and ph probes- Monitor that temperature, pH and oxygen levels remain optimal

water cooled jacket-Keeps mixture at optimum temperature

product out-Product such as insulin, mycoprotein or penicillin is removed from fermenter

Question 24

what is pencicillin

Answer 24

an antibiotic used to control bacterial infections. It kills susceptible bacteria or prevents their growth by disrupting the production of the bacterial cell wall. This weakens the bacteria and causes them to burst when they divide. (produced in a fermenter)

Question 25

how is penicillin produced

Answer 25

in a fermenter, solution containing sucrose is added to the tank containing Penicillium . This supplies the fungi with the nutrients they need. optimum ph and temp are kept fungi always in optimum conditions to reproduce, As the Penicillium grows, it releases penicillin into its surroundings partial harvesting takes place and carried out many times to maintain high yield

Question 26

simple step by step of penicillin production

Answer 26

1- pencicillium added to fermenter
2- scientist seperate penciillin produced to mold
3- penicillin purified and used for antibiotics

Question 27

how and why are fermenters used to make insulin

Answer 27

to obtain insulin for diabetic patients, using genetically engineered bacteria

Question 27

what is mycoprotein

Answer 27

added to many food products to increase the protein content, cehap and easily made from protein

Question 27

describe genetic engineering

Answer 27

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

Question 28

how is genetic engineering used for insulin production

Answer 28

Human genes can be inserted into bacteria to produce human proteins such as insulin. This protein is used to treat people with type 1 diabetes
-no need to use insulin retrieved from animals, better tolerated by people with the disease

Question 29

how is genetic engineering used for herbicides

Answer 29

insert genes into crop plants that give them a resistance to a herbicide
herbicide can be used where the herbicide-resistant plants are growing. The herbicide-resistant plants are not killed but the weeds are. This means that farmers can reduce the amount of herbicide they use, and the reduced competition with weeds increases the crop yield.

Question 30

how is genetic engineering used for resistance to pests

Answer 30

insert genes into crop plants that give them a resistance to insect pests. eg Bt corn is maize that contains the gene for insect resistance from a soil bacterium
Bt protein does not affect mammals, fish or birds. However, there are concerns related to the use of Bt corn.
however…
-gene can be passed to other plants and they can get the resistant gene may become “super weeds”
-may harm other insects that are not pests and which are an essential part of a food chain.

Question 31

how is genetic engineering used to produce food with better nutritional qualities

Answer 31

increasing their vitamin and amino acid contents, of crop plants
eg. food for livestock has increased amino acids reduces amount of supplements given to animal fro optimal growth
eg. golden rice for vitmamin a defficiency (vitamin a needed for good skin and eye sight, good immune system) insert genes into crop plants that make them produce large amounts of beta-carotene, produces more vitamin a

Question 32

what are disadvantages of golden rice

Answer 32

lead to people and governments not properly recognising the need for a balanced diet

Question 33

what are the main steps in genetic modification

Answer 33

Isolating the section of DNA that makes up the required human gene.(uses restriction enzymes)

Cutting the DNA of a bacterial plasmid.
Inserting the human DNA into the plasmid DNA. (uses restriction enzymes)

Inserting the plasmid into bacteria. (uses ligase enzymes)

Allowing the genetically modified bacteria to express the gene and make the human protein.

Question 34

what enzymes are used in genetic modification

Answer 34

restriction enzymes and ligase enzymes

Question 35

how and why are restriction enzymes used

Answer 35

Enzyme that cuts DNA at specific places to form sticky ends.(The ends of DNA strands after digestion. They easily re-attached to each other, so are called sticky.)

Question 36

how and why are ligase enzymes used

Answer 36

Enzyme that joins DNA at specific places called sticky ends.make a complete length of double-stranded DNA.

Question 37

recombinant plasmid

Answer 37

A plasmid containing a foreign gene or sequence of DNA.

Question 38

disadvantages of genetically modifying crops

Answer 38

expensive, ethical considerations in manipulating nature, unknown long- term effects