Full Flashcards
(10 cards)
Title
The effect of enzyme concentration on substrate reaction.
Aim
To investigate the effect of increasing enzyme concentration (Catalase) on substrate reaction (Hydrogen peroxide).
Underlying Biology (1)
The presence or abundance of certain enzymes End-Product can control metabolic pathways. Feedback inhibition occurs when the end-product in the metabolic pathway reaches an abundance. The end-product then inhibits an earlier enzyme, blocker the pathway and so prevents further synthesis of the end-product.
Underlying Biology (2)
The active site of an enzyme has a strong affinity for the complementary substrate. This means that the substrate has a strong chemical attraction towards the enzyme’s active site. When they come into contact, the substrate fits into the active site, this is due to the enzyme being specific to the substrate and vies versa.
Underlying Biology (3)
Enzyme activity is controlled by molecules known as inhibitors. these inhibitors come in two forms and use different methods to control the activity of the enzyme.
Competitive inhibitors connect directly with the enzyme, this is due to the inhibition molecule being the same shape as the enzymes complimentary substrate. Competitive inhibition is not permanent and can be reversed by increasing substrate concentration.
Underlying Biology (4)
Non-Competitive inhibitors vairy slightly in their method of inhibition. Unlike Competitive inhibitors, they do not connect directly with the active site and instead connect away from the site there by changing the shape of the active site. This stops the given enzymes complementary substrate from being able to join. This action is permanent.
Experimental Proceduree
In each of the 3 test tubes there were different concentrations of Catalase (Enzyme). There was then set volumes of Hydrogen Peroxide (Substrate), as well as set volumes of fairy liquid. Measured by syringes, the fairy liquid was then added followed by the Hydrogen Peroxide. A stopwatch was used to time a set length of the experiment. The volume of foam produced was then measured with a standard ruler, and noted into a table. This was repeated 3 times per Catalase concentration so an average could be produced.
Analysiss
From the results I have gathered from both my own experiment as well as my experimental research reference, it is clear that catalase (enzyme) concentration has a direct effect on the volume of foam produced and there for the rate of reaction. From my own data I calculated the percentage of the average increase form the lowest concentration of catalase measured (100 Units) to highest concentration (1000).
Percentage Inc = difference/original x 100:
= 5.66mm, 98mm
dif= 98-5.66 = 92.34
og= 5.66
=92.34/5.66x100 = 1631 %
This shows the reaction rate increase substantially by 1631 % as the concentration of catalase increased from 100 Units to 1000 Units.
The results from the online source showed similar results of increasing catalase concentration on Hydrogen Peroxide. This there by shows that increasing the enzyme activity impacts the substrate reaction.
Conclusion
As the enzyme (Catalase) concentration is increased, the substrate reaction also increases. This is shown by the volume of foam production increasing, As the catalase units was increased. The more foam produced, the greater the substrate reaction.
Evaluation
In evaluation of my experiment and the results I measured I believe that experiment and data gathered was pretty reliable. This is because I adopted some recognised experimental producers to ensure the integrity of my data. I completed the experiment three times per enzyme concentration so average values could be produced. This is more reliable than only conducting the experiment once.
I also used the same time scale for each iteration of my experiment, this ensured that the enzymes and substrates had enough time to react with each other and showed the effect which catalase (enzyme) concentration had on hydrogen peroxide reaction.
However, there are some improvements I would do if I was to repeat this experiment. Firstly I would make sure that temperature was controlled and kept at a constant throughout the experiment; this is because enzyme activity is effected by temperature To do this I would utilize water baths. This would ensure that the enzyme and substrate reaction was not influenced by a varying temperature and would improve the validity of the results.
Secondly, I would ensure that the PH levels though out the experiment were also kept at a constant, as like temperature Ph can have a significant impact on enzyme activity. If I had of measured and maintained a constant ph during my experiments I could have seen a greater constant in my results which would of further validated my data.
