The Effect of Substrate Concentration on the Rate of Reaction
Aim:
The aim is to look at how the rate of reaction in yeast catalase is affected by a particular substrate concentration. The substrate that is used in this experiment is hydrogen peroxide on the yeast catalase, which will bring faster and more precise results.
Enzymes only work with substrates that fit their active site, called the lock and key mechanism. This is where the substrate fits into the enzyme in the same way that a key fits into a lock. During the process, a substrate is fitted into an active site of an enzyme. Not all substrates fit in, only particular ones, hence, the ‘lock and key’. When they are together, the enzyme – substrate complex is made into a product. This is when the bonds in the substrate are weakened. The products are left from the enzyme, leaving the enzyme unchanged after the reaction.
The reaction is a catabolic reaction, which means the yeast catalase breaks down the hydrogen peroxide into water and oxygen gas.
H₂O₂ H₂O + O₂
Apparatus Used:
1. Stop watch.
2. Measuring Scale.
3. Stand with clamps.
4. Gas syringe.
5. Measuring cylinder.
6. Clonical flask.
7. 1.5 grams of yeast catalase.
8. 4 cm³ of hydrogen peroxide of various concentrations.
