Which type of chemistry studies the chemical reactions that occur in the human body?

The type of Chemistry that studies the chemical reactions that occur in the human body, is Biochemistry.

Explanation:

That is true ofcourse so yes

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.