Amin Shahiri 12AW
Biology AS Enzyme Concentration Assignment
Enzyme Reaction Rates
Aim:
To investigate the effect of substrate concentration on an enzyme reaction rate, how it varies at different concentration solutions
Background Information:
- Enzymes such as Catalase are protein molecules, which are found in living cells. They are used to speed up specific reaction within the cell. They are all very specific as each enzyme just performs one particular reaction.
- Catalase is an enzyme found in food such as potato and liver. It is used for removing Hydrogen Peroxide from cells. Hydrogen Peroxide is the poisonous by-product of metabolism. Catalase speeds up the decomposition of Hydrogen Peroxide into water and oxygen.
- It is able to speed up the decomposition of Hydrogen peroxide because the shape of its active site matches the shape of the Hydrogen peroxide molecule. This type of reaction where a molecule is broken down into smaller pieces is called an Anabolic Reaction.
Prediction:
From my own knowledge about this experiment I predict that if catalase enzymes in the potatoes and the temperature are kept constant at all time through the experiment, the increase of PH solution concentration in this case Hydrogen Peroxide will result in higher rate of reaction with more oxygen volume retrieved in the limited time. Basically as substrate concentration increases, the initial rate of reaction also increases. The more substrate molecules are around, the more often enzyme’s active site can bind with one. However if we go on increasing substrate concentration, keeping the enzyme concentration constant, there comes a point where every enzyme active site is working continuously. If more substrate is added the enzyme simply cannot work faster, substrate molecules are effectively ‘queuing up’ for an active site to bond with and become complex.
The enzyme is working at its maximum possible rate, which is also known as V max,
so further increase in substrate concentration will no longer affect the rate of reaction.
