What happens to wort when boiled in kettle？

The wort after lautering must be boiled in stainless steel brew kettle for 1-2 hours. And during boiling, the brewmaster would add a certain hops in order to give beer mouthful bitterness and happy aroma. Do you know what changes come to wort during boiling?

• Dissolute and transform the bitterness of hops;

• Form and separate the polyphenol compounds;

• Evaporate excess water and keep the wort to reach specified wort concentration;

• Sterilize the wort;

• Destroy the enzyme activity thoroughly and immobilize the wort components;

• Improve the beer color;

• Increase the beer acidity;

• Form reductive substance;

• Change the content of DMS.