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Importance of enzymes in living organisms
The role of enzymes in biological systems essay
The role of enzymes in biological systems essay
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Investigating the Activity of an Enzyme
Sucrose using the enzyme sucrase (invertase) can be broken down into
Glucose and Fructose. The aim of this experiment was to find about the
activity of enzymes through measuring the micromoles of sucrase
expressed whilst the following reaction occurs:-
SUCRASE
[IMAGE]SUCROSE GLUCOSE + FRUCTOSE
C12H2201 H20 C6H12O6 C6H12O6
The progress of this reaction was monitored using Dinitrosaylic Acid
(DNS) as the reagent reacts with the reducing sugar products. The
colour of DNS changes from yellow to varying shades of red; depending
on the on the reducing sugars product being found with time.
The light absorption from the varying colours of solutions can then be
measured calorimetrically.
A standard calibration curve could then be used to give the results in
units of micromoles.
Method
As described in schedule.
Results
Tube Number
1
2
3
4
5
6
7
8
Time (in minutes)
0.5
1
2
3
4
5
6
7
Concentration
0.15
0.20
0.36
0.40
0.49
0.58
0.60
0.61
Absorbance in nm*
0.248
0.333
0.611
0.675
0.85
1.126
1.176
1.226
(Green filter No. 604)
Please see graph.
Discussion
The graph shows at room temperature and under neutral pH, the enzyme
intervase catalysis the splitting of sucrose into fructose and
glucose, the products. It also shows the higher the concentration the
greater number of molecules will react with each other. The amount of
sucrose and enzyme govern the time for the reactions to take place.
If enzyme concentration is increased the sucrose will more quickly
start breaking down as it has more particles to react with.
Data from Table 1. confirms the theory that as the concentration of glucose increases so will the absorbance of the solution when examined with the glucose oxidase/horseradish peroxidase assay. Glucose within the context of this assay is determined by the amount of ferricyanide, determined by absornace, which is produced in a one to one ratio.1 Furthermore when examining the glucose standards, a linear calibration curve was able to be produced (shown as Figure 1). Noted the R2 value of the y = 1.808x - 0.0125 trend line is 0.9958, which is statistically considered linear. From this calibration curve the absorbance values of unknowns samples can be compared, and the correlated glucose concentration can then be approximated.
This evidence alone suggests that higher increases in substrate concentration causes smaller and smaller increases in enzyme activity. As substrate concentration increases further, some substrate molecules may have to wait for an active site to become empty as they are already occupied with a substrate molecule. So, the rate of the reaction starts to level off resulting in a plateau in the graphs. This means that the reaction is already working at its maximum rate, and will continue working at that rate until all substrates are broken down. The only way the reaction rate would increase, is if more enzyme was added to the solution. This confirms that increases in substrate concentration above the optimum does not lead to greater enzyme activity. Therefore, the rate of reaction is in proportion to the substrate
Overall, as the concentration of the substrate increases, the enzyme activity increases up to a 70% of solution, where the enzyme activity starts to level off. The curve is polynomial because of the fact that the enzyme activity exponentially increases as the concentration of substrate increase; additional evidence for this is the fact that the gradient graph is constantly changing. The polynomial curve is shown because until 70% (the saturation point); this is because there are more casein substrate molecules that can successfully collide with the renin enzyme molecule, therefore increasing the rate of reaction.
Rate of Respiration in Yeast Aim: I am going to investigate the rate of respiration of yeast cells in the presence of two different sugar solutions: glucose, sucrose. I will examine the two solutions seeing which one makes the yeast respire faster. I will be able to tell which sugar solution is faster at making the yeast respire by counting the number of bubbles passed through 20cm of water after the yeast and glucose solutions have been mixed. Prediction: I predict that the glucose solution will provide the yeast with a better medium by which it will produce a faster rate of respiration. This is because glucose is the simplest type of carbohydrate (monosaccharide).
Enzymes are proteins that increase the rate of chemical reaction by lowering their activation energy. The enzyme glucose oxidase is one of the most widely used enzyme as an analytical reagent due to its ability to identify the presence of glucose, its low cost and good stability. This report discusses the role of enzymes concentration in biological reactions and the catalytic activity of glucose oxidase on D-Glucose. The activity was studied by spectrophotometry and the results were first tabulated and then plotted. The results of this experiment indicate that the enzyme concentration has no major affect on the rate of
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.
The independent variable for this experiment is the enzyme concentration, and the range chosen is from 1% to 5% with the measurements of 1, 2, 4, and 5%. The dependant variable to be measured is the absorbance of the absorbance of the solution within a colorimeter, Equipments: Iodine solution: used to test for present of starch - Amylase solution - 1% starch solution - 1 pipette - 3 syringes - 8 test tubes – Stop clock - Water bath at 37oc - Distilled water- colorimeter Method: = == ==
Investigating the Effect of Substrate Concentration on Catalase Reaction. Planning -Aim : The aim of the experiment is to examine how the concentration of the substrate (Hydrogen Peroxide, H2O2) affects the rate of reaction. the enzyme (catalase).
In this experiment as a whole, there were three individual experiments conducted, each with an individualized hypothesis. For the effect of temperature on enzyme activity, catalase activity will be decreased when catalase is exposed to temperatures greater than or less approximately 23 degrees Celsius. For the effect of enzyme concentration on enzyme activity, a concentration of greater or less than approximately 50% enzymes, the less active catalase will be. Lastly, the more the pH buffer deviates from a basic pH of 7, the less active catalase will be.
Investigating the Effect of Enzyme Concentration on the Hydrolysis of Starch with Amylase Aim: Investigate the effect of enzyme concentration on the rate of an enzyme-controlled reaction. Using amylase and starch as my example. Introduction: I am investigating the effect of the concentration of the enzyme, amylase on the time taken for the enzyme to fully breakdown the substrate, starch to a sugar solution. The varied variable will be the concentration and all other variables are going to be fixed. The different concentrations will be: 0.5% 0.75% 1.0% 1.5% 2% An enzyme is a class of protein, which acts as a biological catalyst to speed up the rate of reaction with its substrates.
Investigating a Factor that Affects Enzyme Activity Planning -------- Aim --- To investigate a factor which will affect the activity of catalase, whilst keeping all variables constant. Possible Independent Variables ------------------------------ Here are a number of possible independent variables that could be changed in the experiment: Independent variable Continuous/Discontinuous Easy to measure?
This lab attempted to find the rate at which Carbon dioxide is produced when five different test solutions: glycine, sucrose, galactose, water, and glucose were separately mixed with a yeast solution to produce fermentation, a process cells undergo. Fermentation is a major way by which a living cell can obtain energy. By measuring the carbon dioxide released by the test solutions, it could be determined which food source allows a living cell to obtain energy. The focus of the research was to determine which test solution would release the Carbon Dioxide by-product the quickest, by the addition of the yeast solution. The best results came from galactose, which produced .170 ml/minute of carbon dioxide. Followed by glucose, this produced .014 ml/minute; finally, sucrose which produced .012ml/minute of Carbon Dioxide. The test solutions water and glycine did not release Carbon Dioxide because they were not a food source for yeast. The results suggest that sugars are very good energy sources for a cell where amino acid, Glycine, is not.
The mixture for that table’s flask was 15 mL Sucrose, 10 mL of RO water and 10 mL of Yeast, which the flask was then placed in an incubator at 37 degrees Celsius. In my hypothesis for comparison #4 the measurements would go up again with every 15 min. intervals because of the high tempeture and also be higher that then Controlled Table’s measurements. Hypothesis was right for the first part but was wrong for the second part of the comparison, the measurements did increase in the table’s personal flask but the measurements did not get higher than the Controlled Table’s measurements, see chart below. In conclusion, I feel that the substitution of glucose for sucrose made the enzymes work just as hard as the Controlled Table’s flask but just not as much because sucrose was too strong for the enzymes to
By using spectrophotometer, the effect of enzyme and substrate concentrations were predicted. The experimental design was to observe the effect of particular substrate concentrations on tyrosinase enzyme activity. Any changes in amount of product formed over a time, depended upon the level of enzyme present. Likewise, an enzyme is very specific meaning that, it can recognize its substrate from even closely related isomers. The specificity of tyrosinase for the substrate tyrosine is not high. In fact, it reacts with a variety of ring structures and one of them is Catechol. Sucrose is not affected by the tyrosinase enzyme. So it was hypothesized that there will be no brown color as production when sucrose will be involved. On the other hand,
Researchers then hypothesized that the results would indicate the greatest amount of potato enzyme activity level will take place at room temperature. In this experiment, researchers used potato extract and different temperature levels to test the hypothesis. Moreover, researchers wanted to test the color intensity scale and how specific catechol oxidase is for catechol. In this experiment, researchers used dH2O, catechol solution, hydroquinone, and potato extract. Lastly, researchers tested the substrate concentration and how it has an effect on enzyme activity.