Thread: what is more likely to ferment the fastest, glucose of fructose and why?? Also i read somewhere that as yeast grows, genes become switched on. Can someone please elaborate on this :)

what is more likely to ferment the fastest, glucose or fructose and why?? Also i read somewhere that as yeast grows, genes become switched on. Can someone please elaborate. Thank you



This is for coursework i am doing at school and i am slightly confused on what to include

Ask youself what sugar does alchohol fermentation act on? What is fructose?

Draw out the steps.....

Does glucose ferment quicker as it does not need to be converted whereas fructose needs to be converted into glucose in order to ferment, therefore taking longer?

But how can i write a whole coursework project on this? My explanation is not very scientific

Yes!

Not sure what you mean by coursework project, but you could develop an experiement which test the idea. For example, you could look at the amount of CO2 released over time that compares fermentation rates for the different types of sugars and controls. Experiments are great for teaching.

Thats exactly what i'm doing, i'm comparing the effect of glucose and fructose on yeast fermentation by measuring the amount of carbon dioxide. Do you understand how yeast begins to grow, its genes become switched on?, could you explain this to me please

Thank you

Get a hydrometer. You can find one at any home brewing supply store. It will tell you the amount of dissolved sugar before and after the fermentation.

i have never come across a home brewing supply store

I believe fructose ferments the fastest, I did this grade 12 fermentation lab just a few weeks ago.
I am not even sure if I am right as the teacher havn't handed my lab back but this was what I wrote, see if it helps:

"Fructose gets converted to carbon dioxide the fastest because it can skip step one in glycolysis where glucose gets converted to glucose six phosphates then to fructose six phosphates. The reason why sucrose is slower than glucose and fructose is because it is a disaccharide sugar made up of glucose and sucrose, the yeast probably has to break the bonds first then process glucose and fructose separately. My theory of why the yeast has trouble digesting the sweetener is because it is a big polysaccharide sugar made up of glucose that can be digested slowly by the yeast. And Starch cannot be fermented at all because it is way too big for the yeast enzymes to break."

https://www.dropbox.com/s/cyxsbdpqi3...ion graph.docx
And this my actual experiment data if you want to reference it
I think it has something to do with CO2 emission or something, I forgot :L

Hope it helped :P

PS For your yeast on/off gene thing. My teacher is currently teaching the genetics unit, I am guessing that MAY have something to do with gene regulations, try look up key words like operons + yeast. For all I know lac operon controls the E Coli lactose digestion, that's something to start digging