Yeast Enzyme Denaturing

[blueyedevil]

At what temperatures does the yeast enzyme denature? Both the hottest temperature and the coldest temperatures they can withstand before denaturing.
Thanks

[theprof]

Which yeast? Which enzyme?

[Alfee]

In low temperatures enzymes do not denature, but just slow down, in the break down (catabolic) or build up (anabolic) of substances.

Normally enzymes work best between the temperatures 30-40 degrees C. Above these optimum temperatures the enzymes will start to denature. However I do not know the exact figures for yeast in particular.

I hope this has helped a little.

[theprof]

OK, I'll try again, but I'll make a couple of assumptions.

There are a considerable number of enzymes in Saccharomyces cerevisia, which is the conventional yeast used in baking and brewing. I take it this is the species you are referring to.

The "enzyme" most commonly referred to in this yeast is Zymase. This has an optimum working temperature of around 38 degrees C. The particular strain involved can make a slight difference.

Progressive denaturing of Zymase will occur above this temperature and all enzyme activity will cease around 60 to 70 degrees C.

A set temperature for denaturing Zymase does not really exist as it depends on a number of factors including substrate, enzyme age etc. This is why class experiments held months apart often show different results.