harnessing biology

Question 1

what is a bacteria’s cell wall made of

Answer 1

murein

Question 2

what are the circle structures called in a bacteria’s cell

Answer 2

plasmids - circle of DNA - for genetic modification

Question 3

what is a fungi’s cell wall made of

Answer 3

chitin

Question 4

what antibiotic does the fungi: Penicillium produce

Answer 4

penicillin (aerobic respiration)

Question 5

what is bacteria genetically engineered to produce

Answer 5

human insulin (aerobic respiration)

Question 6

what is the purpose of a cooling jacket

Answer 6

• respiration produces heat
• therefore cooling jacket cools it down to optimum temperature

Question 7

what is the use of having sterilisation and an air filter in the industrial fermenter

Answer 7

• both remove unwanted bacteria (through super heated steam)
• sterilisation - gets rid of other unwanted bacteria as it could create competition for the nutrients

Question 8

what is the use of a stirrer for mixing in the industrial fermenter

Answer 8

distributes heat and nutrients

Question 9

why is it important to add air and nutrients (growth medium) to the fermenter regularly

Answer 9

-allows bacteria to respire aerobically through oxygen and glucose
- amino acids - protein
(glucose and amino acids - protein are nutrients)

Question 10

what would change about the design of the industrial fermenter if you were producing beer/ethanol

Answer 10

• no oxygen - for anaerobic respiration
• glucose -> ethanol + CO2

Question 11

what role does yeast play in bread and beer making

Answer 11

bread - produces CO2
beer - produces ethanol

Question 12

how could someone increase the speed of respiration in the yeast and making the dough rise more rapidly

Answer 12

• increase temperature
• increases kinetic energy
• increases number of collisions between substrate and active site of enzyme

Question 13

how could you improve the validity of your investigation:
experiment - measuring the rate of anaerobic respiration in yeast cells

Answer 13

• repeats = increase in reliability
• volume of gas = more accurate (bubbles different sizes)
• more temperatures - to find accurate optimum

Question 14

what is the word equation for anaerobic respiration in yeast?

Answer 14

glucose -> carbon dioxide + ethanol

Question 15

what is the word equation for anaerobic respiration in animals?

Answer 15

glucose -> lactic acid

Question 16

describe 3 conditions of a fermenter (paddle, sterile, temp)

Answer 16

paddle - distribute nutrients/heat
sterile - super heated steam
optimum temperature - for enzymes

Question 17

yoghurt is made using what bacterium

Answer 17

Lactobacillus bulgaricus

Question 18

is lactobacillus bulgaricus unicellular or multicellular

Answer 18

unicellular

Question 19

does lactobacillus bulgaricus have bound organelles

Answer 19

no

Question 20

what shape is the lactobacillus bulgaricus’ chromosome (nucleotide)

Answer 20

circular

Question 21

what does sterilisation/pasteurisation do in the process of making yoghurt

Answer 21

kills unwanted bacteria

Question 22

how is the sterilisation done in the process of making yoghurt

Answer 22

heated to 95 degrees celsius

Question 23

milk is h_________ (stirred up) to d_______ f__ g_______

Answer 23

homogenised
disperse fat globules

Question 24

what is the temperature for optimum enzyme activity in lactobacillus

Answer 24

40 degrees celsius

Question 25

if temperature stayed at 95 degrees celsius what would happen to the lactobacillus

Answer 25

it would die - enzymes denature

Question 26

the lactobacillus d_____ m____ p______ and respire the l____ (sugar) to l____ a___ (fermentation) - a_________

Answer 26

the lactobacillus digest milk proteins and respire the lactose (sugar) to lactic acid (fermentation) - anaerobic

Question 27

lactic acid has a ____ pH - this does what to the milk proteins and therefore to the yoghurt

Answer 27

lactic acid has a low pH (acid) and therefore denatures the milk proteins, causing the yogurt to thicken

Question 28

the yoghurt is cooled to preserve it - why does this work and what else would also slow down activity of bacteria

Answer 28

low temperature SLOWS down ENZYNE ACTIVITY and GROWTH of bacteria LOWER pH also slows down activity of bacteria

Question 29

what are the key points of making yoghurt (talk about: bacteria, respiration and the product)

Answer 29

- the bacteria carry out an aerobic respiration - they respire LACTOSE (sugar) instead of glucose - the product is lactic acid

Question 30

what is the equation for anaerobic respiration in (SOME) bacteria

Answer 30

lactose -> lactic acid