21- Biotechnology

Question 1

biotechnology

Answer 1

a technique that uses living organisms to carry out processes to make substances we need, eg: food, enzymes

Question 2

genetic engineering

Answer 2

changing the genetic material of an organism (usually microorganisms ) by removing, changing or inserting genes

Question 3

advantages of using bacteria in biotechnology and genetic engineering

Answer 3

1- tiny, easy to grow in labs
2- no ethical issues over their growth
3- they share the same DNA as humans
4- they can make complex molecules
5- they have additional DNA ( plasmid ), which is easy to transfer between cells
6- reproduce rapidly

Question 4

yeast

Answer 4

• single celled fungus that uses sugar as its food source

- respire anaerobically

Question 5

uses of yeast

Answer 5

make alcohol as biofuel, bread making

Question 6

respiration of yeast

Answer 6

anaerobic respiration (fermination)
glucose ---> ethanol + CO2 + energy

Question 7

biofuel

Answer 7

a fuel made from living organisms rather than a fossil fuel

Question 8

substrate for producing ethanol

Answer 8

plant material (as a source of glucose)- maize

Question 9

how is plants (maize) used in producing ethanol

Answer 9

1. maize is treated with amylase to break down starch to
   glucose.
2. yeast is added for anaerobic respiration for glucose to
   produce ethanol.
3. ethanol is extracted by distillation.

Question 10

advantages of using ethanol as a fuel

Answer 10

1. it is sustainable resource.
2. helps to reduce CO2 from air as we plant more maize.
3. does not cause pollution

Question 11

disadvantages of using ethanol as a fuel

Answer 11

Maize needs large lands to grow, instead of growing food for people, so it will be expensive for people to buy food.

Question 12

what makes the bread dough rise

Answer 12

Carbon dioxide produced by respiration of yeast

Question 13

function of amylase in dough

Answer 13

break down starch into starch into maltose and glucose

Question 14

what makes the dough stretchy

Answer 14

gluten (protein)

Question 15

what gives the smell of bread

Answer 15

the alcohol (ethanol) evaporating

Question 16

advantages of using biological washing powders

Answer 16

1- quick breakdown of insoluble materials into soluble ones.
2- effective at low temperatures, requiring less energy and money, and can be used on delicate fabrics that would be damaged by high temperatures

Question 17

enzymes present in biological powders and their uses

Answer 17

1-protease - catalyses breakdown of protein, eg; blood

2-lipase - catalyses breakdown of fats,eg; greasy stains

Question 18

why are enzymes in biological powders kept on capsules

Answer 18

to prevent them from reacting with proteins and fats in peoples skin

Question 19

enzymes used to extract juices from fruits

Answer 19

pectinase - breaks down pectin, makes juice clearer

Question 20

pectin

Answer 20

substance in cell wall of a plant which helps plant cells stick together

Question 21

lactose

Answer 21

disacchride sugar found in milk

Question 22

lactase

Answer 22

enzyme that breaks down lactose

Question 23

lactose intolerant

Answer 23

loose the ability to produce lactase

Question 24

symptoms of lactose intolerance

Answer 24

nausea, flatulence and diarrhoea

Question 25

how is lactose free milk made

Answer 25

lactase enzyme is added into it and left for a while to breakdown the lactose

Question 26

products of breakdown of lactose

Answer 26

glucose and galactose- make milk sweet

Question 27

penicillin

Answer 27

an antibiotic that kills bacteria (interferes with the building of the bacterial cell wall )- the first one discovered

Question 28

how is penicillin produced

Answer 28

by growing the fungus Penicillium in industrial fermenter

Question 29

fermenter

Answer 29

containers used to grow (‘culture’) microorganisms like bacteria and fungi in large amounts

Question 30

advantage of using fermenter

Answer 30

conditions can be controlled

Question 31

advantages of modifying crops

Answer 31

1- golden rice help people not suffer from blindness
2- increase crops yields
3- reduce labor costs (cheaper food)

Question 32

disadvantages of modifying crops

Answer 32

1- no enough money to buy this food
2- gene might spread to weeds to produce weeds which are resistant to herbicides.
3. eating these crops may harm people’s health, because they contain toxin which kills insects.
4. some insects may become resistant to the toxin.

Question 33

plasmid

Answer 33

circular ring of DNA found in bacteria, which is physically separated from chromosomal DNA

Question 34

how are insulin genes from humans extracted

Answer 34

by restriction enzymes- they cut DNA and leaves sticky ends