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In the fermentation experiment.. (1 Viewer)

Tommo90

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Hey this is my first post! Exciting.. kind of.

I just have a quick question.. how would you account for 'no air' in a fermentation experiment?
 

Trebla

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An appropriate seal to prevent air (i.e. oxygen) entering the system.
 

Tommo90

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Well, fermentation occurs without the presence of air.. and i can't remember how air didnt affect the fermentation process in our experiment.. Possibly the apparatus used prevented air from coming into contact with the glucose yeast solution however i'm not too sure how that would have worked.

Another thought I had was, 'Can fermentation still occur with air present, just not as well?'

In the syllabus it says you need to be able to plan an investigation to carry out the fermentation of glucose.. and air is to be excluded as a condition of the fermentation process. As part of my plan for this experiment, i don't know how air would be excluded

And in reply to Trebla.. isn't there air/oxygen already present within the conical flask containing the glucose yeast solution?

Lol sorry that's a lot of talking over a small deal but can anyone help?
 

gerg tenrab 07

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yes there is air in the conical flask but it gets quickly used up and if no more air is allowed to get in then fermentation can continue with no air
 

xiao1985

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my theory is yeast can undergo aerobic respiration as well as anaerobic respiration...

when there is air, it will undergo aerobic respiration... this does not produce ethanol, and hence should be avoided...

additionally, introduction of air will cause ethanol to slowly oxidise, and turn it into ethanoic acid (vinegar)
 

xiao1985

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with air: no ethanol

without air: ethanol

------------------------------

even if ethanol is produced with the prescense of air, air will oxidise ethanol to vinegar
 

Tommo90

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lol i think you must have misinterpreted what i was asking :p i was asking how you could make the experiment anaerobic
 

xiao1985

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@ tommo: sorry my bad

@lucid: lol what a legend... thanks for the answer... it was quite novel equipment set up...
 

Budz

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Wow love for chem..
havent been here in like a year.
And i dont know why i am here now.
will
 

elseany

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i dont think you understand wahts happening exactly.

basically fermentation is a way for the yeast to get energy when there is no oxygen around. They still can breath (respirate) in air but are lucky enough to also be able respirate in the absence of air.

so for this experiment you can just get your fermenation mixture and put it in a flask and put your stopper ontop so no more air can get in. What happens then is that the yeast will consume the oxygen and the flask will then become an anaerobic environment suitable for fermentation (Y).
 

matsabatsa

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We just did ours in a conical flask with a rubber stopper in the top and a tube for the co2 testing ( into limewater)
 

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