biotech

Question 1

Explain why oxygen is bubbled through the tank at this stage?

Answer 1

mixes microorganisms with sewage ;
good contact between microorganisms and solids ;
more collisions ;
(aerobic) respiration ; R if anaerobic respiration
microorganisms produce carbon dioxide ;
gain / release / transfer, energy ;
(for) growth ;
(for) reproduction ;
to make enzymes ; A ref. to digestion

Question 2

State why it is important that sewage is treated?

Answer 2

prevents spread of (named) disease / AW ora ;
avoids pollution / removes harmful substances ;
makes, water / sewage / effluent, safe / AW ;
avoids smells ;
recycling of water ;

Question 3

Describe how bacteria are used to produce enzymes for washing powders?

Answer 3

(bacteria grown in) fermenters ;
(bacteria provided with) substrate / food (substances) / glucose /
minerals / whey / waste substances / nutrients / culture medium /
AW ;
oxygen / aerobic conditions ; A air bubbled through
(bacteria) grow / reproduce / increase in number ;
enzymes, secreted / released / AW ;
enzymes separated from, bacteria / mixture ; A ref to filtration
AVP ; e.g. conditions – 26°C / pH 5–6

Question 4

Advantages of using pectinase in fruit juice production?

Question 5

How do strains of antibiotic resistant bacteria develop?

Answer 5

Gene mutation
Bacteria becomes resistant to antibiotic
Due to resistance it’s able to survive and reproduce
Passes the resistance to the next generation