The Concentration of Hydrogen Peroxide and Speed of The Rate at Which It is Broken Down by Catalase
AIM
To find out whether the concentration of Hydrogen Peroxide affects the
rate of decomposition of hydrogen peroxide when broken down by
catalase.
SCIENTIFIC KNOWLEDGE
Hydrogen peroxide is a liquid bi-product of many chemical reactions in
living things. It is toxic, so has to be broken down by the enzyme
catalase which is also found in most living things. E.g.
[IMAGE]Hydrogen peroxide catalase water + oxygen
2H2O2 (aq) 2H2 O + O2
[IMAGE]
The enzyme catalase (peroxidase) was the first enzyme discovered and
is one of the fastest enzymes, its turnover rate is about 40,000
molecules/second. It speeds up the decomposition of hydrogen peroxide.
· Enzymes are not used up by the reaction and remain unchanged.
· Enzymes work most efficiently at their optimum temperature and
optimum pH, which from a previous experiment, I know to be about pH8
· Can be denatured (changed in shape) by excess heat (+45°C) and/or
extremes of pH.
· Very specific to their substrate molecule.
THEORY
COLLISION THEORY
Enzymes are biological catalysts. They tend to speed up the rate of
biochemical reactions.
Decomposition of hydrogen peroxide
[IMAGE]2H2O2 (aq) 2H2 O + O2
The enzyme catalase (peroxidase), catalase was first enzyme
discovered. It is one of the fastest enzymes, with a turnover rate of
about 40,000 molecules/second.
Speeds up the rate of decomposition of hydrogen peroxide
[IMAGE]
[IMAGE]
[IMAGE][IMAGE][IMAGE] active site
[IMAGE]
catalase hydrogen peroxide
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9
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5
2.5
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12
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2.5
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2.5
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1.5
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0
Conclusion
This experiment was far more accurate than the previous one, however
the results were still well off what would be expected for 25vol. This
leads me to believe that something else is affecting that experiment.
For the second experiment all of the hydrogen peroxide concentrations
were made up at the same time, so this would not have been a factor.
The first three results were just about perfect, each doubling. This
shows that whatever it is that is causing the change in the pattern,
only affects the strongest concentrations.
The results of this experiment showed a specific pattern. As the temperature increased, the absorbance recorded by the spectrophotometer increased indicating that the activity of peroxidase enzyme has increased.At 4C the absorbance was low indicating a low peroxidase activity or reaction rate. At 23C the absorbance increased indicating an increase in peroxidase activity. At 32C the absorbance reached its maximum indicating that peroxidase activity reached its highest value and so 32 C could be considered as the optimum temperature of peroxidase enzyme. Yet as the temperature increased up to 60C, the absorbance decreased greatly indicating that peroxidase activity has decreased. This happened because at low temperature such as 4 C the kinetic energy of both enzyme and substrate molecules was low so they moved very slowly, collided less frequently and formed less enzyme-substrate complexes and so little or no products. Yet, at 23 C, as the temperature increased, enzyme and substrate molecules
The purpose of this study is to analyze the activity of the enzyme, catalase, through our understanding
In both solutions of catalase there is a steady increase in reaction relative to the hydrogen peroxide concentration as it increases. A significant jump is observed in the carrot catalase solution between .25% and .5% whereas the pinto bean catalase solution has a steady increase. Each solution doesn’t generate much more reaction to the next increment of hydrogen peroxide concentration, 1%. In general it stayed level. This continued to be a trend for the pinto bean catalase solution, plateauing through to the 6% concentration of hydrogen peroxide. This is known as the point of saturation.
To determine the effects of two environmental factors, temperature and pH, on the enzyme peroxidase, a spectrophotometer was used to measure the absorbance of each reaction every twenty seconds for two minutes. The temperatures tested were 0°C, 23°C, 32°C, and 48°C; the pH levels tested were pH 3, pH 5, pH 7, and pH 9. The temperatures were kept constant by keeping the tubes at room temperature, or placing them in an ice bath, warmer, or a hot water bath. Peroxidase, hydrogen peroxide, guaiacol and a pH buffer were mixed together to produce a reaction for both the temperature and pH experiments.
It is important however to note that the NH4 and K ions are still in
The Effect of pH on the Activity of Catalase Planning Experimental Work Secondary Resources Catalase is a type of enzyme found in different types of foods such as potatoes, apples and livers. It speeds up the disintegration of hydrogen peroxide into water because of the molecule of hydrogen peroxide (H2O2) but it remains unchanged at the end of the reaction.
Abstract: Enzymes are catalysts therefore we can state that they work to start a reaction or speed it up. The chemical transformed due to the enzyme (catalase) is known as the substrate. In this lab the chemical used was hydrogen peroxide because it can be broken down by catalase. The substrate in this lab would be hydrogen peroxide and the enzymes used will be catalase which is found in both potatoes and liver. This substrate will fill the active sites on the enzyme and the reaction will vary based on the concentration of both and the different factors in the experiment. Students placed either liver or potatoes in test tubes with the substrate and observed them at different temperatures as well as with different concentrations of the substrate. Upon reviewing observations, it can be concluded that liver contains the greater amount of catalase as its rates of reaction were greater than that of the potato.
Investigate the Effect of pH on Immobilised Yeast Cells on the Breakdown of Hydrogen Peroxide
To make this a fair test, we need to keep the same all variables that
A rate is a measure of change that occurs in a given time whilst a
placed in each tube. Each tube was then placed in a water bath of the
How the Concentration of the Substrate Affects the Reaction in the Catalase Inside Potato Cells Introduction Enzymes are made of proteins and they speed up reactions, this means that they act as catalysts. Hydrogen peroxide is a byproduct of our cell's activities and is very toxic. The enzymes in our bodies break down the hydrogen peroxide at certain temperatures they work best at body temperature, which is approximately 37 degrees. At high temperatures, the cells begin to denature. This means that the hydrogen peroxide is prevented from being broken down because they will not 'fit' into the enzyme.[IMAGE] Objective I am going to find out how the concentration of the substrate, hydrogen peroxide affects the reaction in the catalase inside the potato cells.
Investigating the Amount of Oxygen Given Off When Catalase Reacts with Hydrogen Peroxide My aim for this investigation is to measure the amount of oxygen given off when we react catalase (enzyme) with hydrogen peroxide (substrate), this means that I aim to investigate the effect of hydrogen on the activity of catalase. Background Information Enzymes such as Catalase are protein molecules that are found in living cells. They are used to speed up specific reaction in the cell. The enzymes are all very specific as each enzyme performs one particular reaction.
This graph shows the result that I expect to get, I expect to see a
-they were actually separated from each other for (an assumed) few years, not a few days