My results visibly show that the optimum for this enzyme is pH 7, the pH at which the highest rate of oxygen production was obtained, at 0.80 cm3 sec-1, corresponding to the highest peak in the graph. The other rate values obtained from more acidic pHs, for example at pH 2 and pH 4 were much less, measuring 0.02 cm3 sec-1, and 0.07 cm3 sec-1, respectively. This shows that a decrease in pH from the optimum decreases the rate of the reaction. Subsequently, an increase in alkalinity had a similar effect, a decrease in rate, at pH 10 and pH 12, yielded rate values of 0.08 cm3 sec-1, and 0.07 cm3 sec-1, respectively. This shows that an increase in pH from the optimum also decreases the rate of the reaction.
INTRODUCTION: Enzymes are catalysts that speed up reactions by lowering activation energy. Activation energy is the amount of energy needed for a reaction to take place. Enzymes act on substrates which bind to the enzymes’ active site. The enzyme changes its shape to accommodate the substrate which creates the new product. Furthermore, there are optimal conditions which will allow the enzymes to function at its highest rate. These opyimal conditions include temperature, pH levels, and the concentration of the enzyme (Fox, 2013). If the environment is not suited for the enzymes’ optimal conditions then enzymatic reactions cannot occur at its highest rate or may not even react at all. For example, if the temperature is higher than the enzyme’s optimal temperature then the enzyme may become denatured.
We increased the substrate, catechol, while maintaining the enzyme, catecholase, at the same volume. We came to the hypothesis that if the substrate was increased, then the rate of reaction would increase as long as there is enzymes to react with. The third experiment involved how temperature would affect enzyme activity. This was done by placing certain vials in certain temperatures and then analyzing the data in the spectrophotometer. We came to the hypothesis that if the temperature was increased, then the reaction rate would increase until it reaches the optimal temperature after that the reaction rate would decrease. This is because the enzyme will start to denature if the temperatures get too high or too low. The fourth experiment deals with how pH affects enzyme activity. For this experiment different vials with catecholase and different pH’s were observed under a spectrophotometer to see how the enzyme would be affected. We found our hypothesis to be, if pH is raised, then the reaction rate will increase until it reaches the optimal pH. The reaction rate will increase until the optimal pH because after the optimal pH, the enzyme will start to denature and not function as it
How does an enzyme affect reaction rates, and how does the acid affect the enzyme itself? In this most recent catalase lab, data both conclusive and inconclusive answered these questions. In the data collected, the major trend was when the hydrogen peroxide concentration (independent variable) increased, the reaction time (dependent variable) of the enzyme decreased. One of the data points did not follow this trend, and will be addressed later. Also, when the acid was added to the enzyme, the reaction still took place, rendering our data inconclusive. When a paper disk was taken out of the catalase for the first time, it was placed in 100% hydrogen peroxide, which reared quick results. The paper rose in 23.37 seconds, but for the majority of
If the concentration of hydrogen ions is high that means that the pH will be lower and vice versa, a low concentration would mean a high pH. All enzymes are not equally as functional across the spectrum of pH concentration, however each enzyme has it’s own optimum pH at which it is capable of performing its' designated function at the maximum rate. Enzymes sensitivity to pH is determined by the tertiary structure as it determines the shape and charge of the active site. The tertiary structure is formed by the ionic bonds between the amine group, carboxyl group, and the “R” group. (Ms Cooper's A Level Biology). “A change in pH will result in a change of charge on the groups which will untimely result in the bonds breaking and changing the shape of the active site” (Ms Cooper's A Level Biology).
Introduction: Enzymes defined as biological catalysts that speed the chemical reaction by reducing the activation energy (Biology Department, 2014). Enzymes play an important biological role in the cell, as it is important to keep the cell alive by speed up the reaction, which explains why in absence of enzyme some
1. pH. Amino acid side chains contain groups such as - COOH and NH2 that readily gain or lose H+ ions. As the pH is lowered an enzyme will tend to gain H+ ions, and eventually enough side chains will be affected so the enzyme's shape is disrupted. Likewise, as the pH is raised, the enzymes will lose H+ ions and eventually lose its active shape. Many of the enzymes function properly in the neutral pH range and are denatured at either an extremely high or low pH. Some
Enzymes are complex proteins that function as biological catalysts, which act by increasing the rate of biochemical reactions to alter a substance (known as a substrate) in metabolic processes, such as respiration and digestion. In order for enzymes to function at their best, they need their environment to be at
The active sites in enzymes are determined by the arrangement of hydrogen and ionic bonds at –NH2 (amine group) and –COOH (carboxyl group) of the polypeptide chains. Increasing pH converts both the amine and carboxyl groups into neutral groups causing the ionic attraction that forms hydrogen bonds to disappear. This causes the proteins to unfold and change shape and structure. The bonds that are broken form the tertiary structure of the enzyme so if the shape is changed the active site also changes and the substrate no longer fits in the active
There are many factors that may affect enzyme reaction rates. The pH and temperature of the environment that the enzyme is in may denature the enzyme if it is not in the optimal area for the specific enzyme. If the pH and temperature of the environment is in the optimal area than the enzyme will work at its best if not than reaction rates may slow down. In competitive inhibition a competitive inhibitor mimics the substrate. This causes the substrate not to enter the active site of the enzyme. Likewise there is noncompetitive inhibition where a
It decreases the activation energy in reaction. When the substrate binds to the active site on enzyme, it will change the conformation of enzyme to make the enzyme-substrate complex and catalyze reactions2. The reason we want to analyze enzyme kinetic in order to quantitative biocatalysis, understand the catalytic mechanism and understand regulation of
Avi Borad The Effect of pH on Enzyme Activity Introduction: Metabolism is a necessary process in the function of living cells, which is driven by enzymes. Enzymes are catalysts that speed up chemical reactions by lowering the activation energy. Changes in the pH of an environment in which the enzymes act affect their performance capability. The optimum pH is the pH in which the enzymes catalyze the reaction at the fastest rate. The type of enzyme affects its optimum pH. Enzymes are typically denatured in extremely low or extremely high pH ranges, causing them to not function properly. Denaturation is the change in shape of the active site of the enzyme, preventing it from functioning correctly (Laderman et al., 1993).
Each enzyme functions at an optimum pH. Well according to the graph, you see that the enzyme did not function at all when boiled which can be explained by the fact that it got denatured. Denaturing means the secondary and tertiary structure of the enzyme
* Enzyme Concentration Assuming a sufficient concentration of substrate is available, increasing enzyme concentration will increase the enzyme reaction rate. If you increase the enzyme concentration there is more chance of a collision and an increase in the rate of reaction. When there’s more substrate than enzymes (substrate becomes the limiting factor) it will stay at one level.
Annotated Bibliography Source 1 - Worthington Biochemical Corporation, 2015. Effects of pH (Introduction to Enzymes) 2015. Effects of pH (Introduction to Enzymes). [ONLINE] Available at: http://www.worthington-biochem.com/introbiochem/effectsph.html. [Accessed 30 April 2016]. In the article, the Worthington Biochemistry Corporation concisely explain the effects of pH and show what the optimal pH level is for