What happen in each test tube?

[starbuckscoffee]

Test tube 1- 2ml of buffer pH 7 solution + hydrogen peroxide
Test tube 2- 2ml of buffer pH 7 solution + hydrogen peroxide+ 1 drop enzyme
Test tube 3- 2ml of buffer pH 7 solution + hydrogen peroxide+ 1 drop boiled enzyme solution
Test tube 4. 2ml of buffer pH 7 solution + hydrogen peroxide + put into beaker of warm water

Q1. Explain what happened in terms of this eqution- 2H2O2 ---->2H2O +O2

Q2. What are the two controls and there purpose?

[Toothpaste]

Control looks like test tube 1 and also 2?

The enzyme would be catalase right?
It breaks down hydrogen peroxide into water and oxygen.
If you add detergent you would be able to see froth rising up the test tube indicating that the reaction is taking place. (bubbles trap the oxygen produced)

Enzymes generally catalyse reactions - lowering the activation energy needed for a reaction to proceed => speeds it up.

Enzymes are proteins. Boiling it would disrupt/break bonds holding it in its structure and therefore rendering the active site (where the substrate bonds catalysing reactions) useless (substrate no longer fits).

[cns1511]

I just did this prac in biology last week.
Toothpick is right. Test tube 1 and 2 are the controls. They are used to show the reactions (or lack there of) when no experimental conditions have been put in place (ie. The temperatures).
As for the first question: catalase (the enzyme that would have been used) works to break apart the bonds in hydrogen peroxide. Which forms H2O and O2 when the H2O2 decomposes. The catalase (being an enzyme) is used to speed up the reaction to a noticable rate and operates best at pH ~7 and temp ~37 as it is found in the human body (hence has the optimum range related to the human body). Hence temperature changes would effect how well the reaction occurs (enzyme denatures once it exceeds the optimum range and no longer reacts).

Sorry, I started to ramble on a bit there..