Micro-organism growth

Question 1

(1) The microorganism used in the production of mycoprotein is

Answer 1

Fusarium

Question 2

(2) Calculate the difference in the mass of protein contained in 200 g of minced beef compared with 200 g of mycoprotein mince.

Answer 2

20 and 13.5
OR
40 and 27 (1)
= 13.0

Question 3

(1) State one nutritional advantage of mycoprotein.

Answer 3

higher in fibre / source of fibre /

lower in fat (than minced beef)

Question 4

(2) Explain one advantage, other than a nutritional benefit, of using microorganisms to produce food.

Answer 4

produce a large (food) supply / quicker food

Question 5

(6) Explain how optimum conditions for the growth of microorganisms are controlled in a fermenter.

Answer 5

• water (cooling) jacket
• temperature probe
• to maintain an optimum temperature
• inlet pipes for nutrients eg ammonia
• to supply microorganism with food source eg materials to make proteins
• oxygen pumped in
• for aerobic microorganisms or aerobic respiration
• carbon dioxide removed
• pH probe
• alkali added to raise pH
• maintain optimum pH
• paddles
• to evenly distribute nutrients, oxygen and break up clumps of microorganisms
• aseptic conditions
• to prevent contamination of the fermenter
• reduce competition

Question 6

(2) Haemophilia can be treated using a blood clotting factor produced in a fermenter. Explain why one named condition must be controlled in a fermenter.

Answer 6

aseptic conditions (1)
prevent growth of unwanted organisms/prevent contamination(1)
temperature/pH (1)
provide optimal conditions for growth /prevent enzymes denaturing (1)
nutrient levels (1)
provide optimal conditions for growth (1)
aeration/oxygen (1)
for aerobic respiration/ provide optimal conditions for growth / prevent anaerobic respiration (1)

Question 7

(1) Calculate the percentage increase in total cholesterol level in the blood over
this 10-year period.

Answer 7

25.0 %

Question 8

(2) Explain why this man has been advised to eat mycoprotein rather than meat.

Answer 8

to lower cholesterol levels/the
man’s cholesterol level exceeds
government recommended levels
(1)
(mycoprotein) lower in {fat /
saturated fat} / mycoprotein
contains {no/less} cholesterol
(1)
which reduces chances of heart
attack / stroke / named health
condition (1)

Question 9

(3) Describe how mycoprotein is produced.

Answer 9

use of fermenter (1)
Fusarium (fungus) (1)
supplied with {sugar
source/ammonia/oxygen} (1)
maintain optimal conditions /
aseptic conditions/without
stirring (1)
(after growth) processed to
produce mycoprotein (1)

Question 10

(6) Using the information in the graph, explain how temperature affects the
fermentation process during yogurt production.

Answer 10

Data trends
 pH of milk is 6.8
 pH reduces to pH 4.5 in 6 hours at 40°C
 pH reduces to pH 4.5 in 9 hours at 20°C
 pH not significantly reduces at 60°C

Interpretation
 fermentation faster at the optimum temperature
 optimum temperature for bacteria growth at 40°C
 enzymes more active at optimum temperature
 no fermentation/bacteria killed/enzymes denature at high temperatures

Yogurt production
 lactose in the milk
 converted into lactic acid
 by bacteria/named bacteria
 reduces pH
 thickens/clots/coagulates the milk