Question

Why does heat impact microbes growth? What are cellular structures impacted by the heat?

Answer 1

See Below

Explanation:

Heat generally speeds up chemical reactions. Chemical reaction rate constants are dependent on temperature (constant at specific temp), so increasing heat usually speeds most of them up.

If that were the only consideration, microbes would grow faster the hotter you got them. So would we.

Heat also has an impact on protein structure. Proteins are a lot like a sweater stitched of one continuous long piece of yarn. Adding heat to a protein can cause that protein to 'denature', which would be like unwinding the sweater. If you take 1 million sweaters and unwind them and stack the yarn together, they will become hopelessly tangled in a jumbled mess - this is a cooked egg.

Also, the cellular membranes of organisms can become suscptible to heat. You and I can't get a temperature above 106F for too long and survive it. It will kill us. It will also kill microorganisms. In our body, this kind of heat causes our cell membranes to basically start to melt (membrane is like a fluid solid wax...too much heat and it melts). This allows your cell contents to leak out and you are dead (this is the principle of the "Heat Shock" process that is done to E coli during cloning experiments).

So heat speeds up chemical reactions, but too much heat will denature your proteins and cause your cell membranes to melt. THese are just a couple of the things affected by heat.