use of biological resources Flashcards
yeast and lactobacillus
what kingdom is yeast found in?
fungi- specific unicellular fungi
what fungus produces the antibiotic penicillin?
penicillium
what else do fungi/bacteria make that is useful for humans?
human insulin
what are the five components of an industrial fermentor?
cooling jacket, air filter, stirrers, growth medium, super-heated steam
what is the purpose of the cooling jacket?
to remove heat energy, to stop the fermentor from overheating and enzymes denaturing
what is the purpose of the air filter?
to filter air coming in, to maintain sterile conditions
what is the purpose of the stirrers?
to keep the broth well stirred to move oxygen, nutrients and microbes around. To also distribute heat evenly.
what is the purpose of the growth medium?
to contain all necessary glucose and amino acids for micro-organisms growth
what is the purpose of the super-heated steam?
this is to be applied before the fermentor is used, to kill any unwanted micro-organisms. only leaves water with no other residue.
what type of respiration is used during beer brewing and bread making?
anaerobic respiration
what is the word equation for anaerobic respiration in yeast?
glucose-> carbon dioxide + ethanol
what does the yeast use in the bread to respire?
sugar
what helps the bread rise and expand the dough during bread making?
bubbles of carbon dioxide
why does ethanol not remain in the bread after cooking?
the high temperatures used during cooking mean that the ethanol evaporates during cooking and doesn’t remain in the bread
describe the steps of the anaerobic respiration experiment?
1-place sugar and add yeast to make a solution, mix to form a suspension, and pour into a boiling tube
3- add a layer of oil on top
4- place in water bath
5- connect a delivery tube to an inverted measuring cylinder and place in a trough of water
6-
why do we place a layer of oil on top of the yeast and sugar solution?
to prevent oxygen entering, whilst allowing carbon dioxide to leave. this ensures its anaerobic.
describe and explain the trend between increasing temperature and volume of carbon dioxide produced?
as temp increases so does the volume of carbon dioxide. this is because the enzymes have more kinetic energy leading to more successful collisions between the active site and substrate and leads to more gas produced.
why does the volume of gas start to decreases as temp increases?
as the enzymes have gone past their optimum point and have now denatured. this means the active site has changed shape so the substrate no longer fits. this therefore decreases the volume of carbon dioxide produced.
how could we increase the validity of this investigation?
use a gas syringe- more accurate for measuring volume of carbon dioxide
use thermostatically controlled water bath- as maintains the correct temp
repeats- 3x and take an average
what is step 1 of the yoghurt making process?
milk is pasteurised to 85-95*c.
why does this occur?
to kill any harmful micro-organisms or those that may turn it into curds and whey
what is step 2 of the yoghurt making process?
the milk is homogenised
why does this occur?
to disperse any globules of fa
what is step 3 of the yoghurt making process?
the milk is cooled to 40-45*c
