effect of temperature on the survival of yeast cells

[reckoner]

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[Ulbrid]

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Meaningful input; much like this one, in fact.

[Teal]

anyone had any ideas on a prediction? thnx 4 any help!

[hippyhiccup]

What if you were to put all the stuff together in a boiling tube... put that in a water bath....wait til it changes colour then taking the temperature... would the results be too flimsy?

[hippyhiccup]

Also; do we have to include actual measurements? Like for example 5mg's of glucose.... if so how much would we use? Does it really matter? i know people were using ratios to explain it but i was wondering how much we're supposed to use.

[Ulbrid]

Also; do we have to include actual measurements? Like for example 5mg's of glucose.... if so how much would we use? Does it really matter? i know people were using ratios to explain it but i was wondering how much we're supposed to use.

It's really up to you to decide. 5-10ml of yeast suspension sounds good; just make sure there's ample hypothetical glucose solution for it to respire with.

[<Singing Mice>]

What if you were to put all the stuff together in a boiling tube... put that in a water bath....wait til it changes colour then taking the temperature... would the results be too flimsy?

i think we have to heat the yeast susp. first and then add the glucose stuff cos then we can measure it at a certain temperature. If you put it all in together first off, its gonna go through a range of temperatures before it gets to the right one. Plus it keeps it fair, cos u can get all ur temps ready, then add the glucose and meth.blue. at the same time.
xxx

[<Singing Mice>]

tip: if ur goona use a microscope to check that the cells are alive / dead, try using a haemocytometer (glass slide with a dip in the middle and grid marked out) so that you can count the cells. Then you can check the concentration of dead cells in the suspension

[Ulbrid]

i think we have to heat the yeast susp. first and then add the glucose stuff cos then we can measure it at a certain temperature. If you put it all in together first off, its gonna go through a range of temperatures before it gets to the right one. Plus it keeps it fair, cos u can get all ur temps ready, then add the glucose and meth.blue. at the same time.
xxx

Sorry, but that's not the best way to do it. It's better when it goes through a range of temperatures because, if it's heated up too quickly, the enzymes could become denatured due to a rapid change in temperature. How does it keep it fair if the temperatures are all ready? I don't understand what you're saying.

[<Singing Mice>]

i meant that surely if they are all 'started off' at the same time, it will keep it more fair. to be honest , there are so many different explanations from everyone and they're all saying summat different that im confused. my teacher said that we had to heat up the susp. first and that it didnt matter about denaturing the enzymes cos they will be denatured anyway if you test a temp of say, 80 degrees C.

[<Singing Mice>]

Oh, another thing- make sure you mention that methylene blue actually inhibits the respiration of of yeast, as it picks up the hydrogen ions produced during the process. the yeast cannot then use the ions to make energy. this could have a confounding effect on your results

[Foo]

Any more pointers you guys want to give me?

i just got this plan this week so it would be pretty handy. For example what IS the temperature that kills all the yeast cells? And what's better, microscope and colorimeter?

Cheers for the help so far