Enzyme Action:
Factors Affecting Enzyme Activity
Carlyssa Warner
September 22, 2017
Life 120L
Abstract
An enzyme is a macromolecule serving as a catalyst, a chemical agent that increases the rate of a reaction without being consumed by the reaction (Urry et al. 2016). pH substrate concentration, enzyme concentration, and temperature affect the reaction rates of enzymes. Very high temperatures denature enzymes. The objective of this lab was to determine what causes changes in enzymes, pH concentration, temperature, or enzyme concentration. It was hypothesized that for when the pH value was changed, and when the substrate level was increased the reaction rate would also increase until the optimum pH was reached. For the change in the enzyme concentration it was hypothesized that if there was an increase in the catalase then there would be an increase in the reaction rate. And the hypothesis for the change in temperature was that if the temperature was increased then the reaction rate would increase until the optimum point was reached, similar to the pH.
Introduction
A catalyst in science is a substance that increases the rate of the chemical reaction. Enzymes are biological catalysts. Enzymes are also proteins. Proteins have the ability to be denatured. Denaturation is when proteins lose their structure. Enzymes are usually denatured above about 45ºC (BBC 2014). The reactant and enzyme acts on is referred to as the enzyme’s substrate (Urry 132). Enzymes have
Enzymes are biological catalysts, which means it decreases activation energy in reactions. The lower activation energy in a reaction, the faster the reaction rate. Many enzymes alter their shape when they bind to the activation site. This is called induced fit, meaning for the enzyme to work to its full potential it has to change shape to binding substrate. The location of enzyme’s activation site is on the surface of the enzyme, where the binding of substrates take place. Enzyme activity can be influenced by a variety of environmental factors. If the concentration of enzyme is low, and there is a great deal of substrate, then increasing enzyme concentration results in more molecules available to convert substrates to products. Thus, increasing enzyme concentration can increase reaction rate. If substrate concentrations are low, and many of the existing enzymes are idle because of a lack of substrate, then adding enzyme will have no effect on reaction rate. Enzyme concentration affects the enzyme activity, because the more enzyme concentration the faster the reaction rate, until it hits it’s limiting factor. When substrate concentration is increased, it also increases rate of reaction. Temperature plays an important
Of the many functions of proteins, catalysis is by far the most vital. When catalysis is not present, most reactions in the biological systems take place very slowly to produce at an adequate pace for metabolising organism. The catalysts that take this role are called enzymes. Enzymes are the most efficient catalysts; they can enhance rate of reaction by up to 1020 over uncatalysed reactions. (Campbell et al, 2012).
These results show how temperature of extreme high, or low affects enzyme activity. The highest rate of enzyme activity occurred at 37 Cº. Anything that was hotter or cold than 37 Cº slowed the reaction rate. As I thought, 100 degrees would denature the enzyme, and that was the case. The data provided shows exactly what temperatures enzymes work best, and worst. The objective was achieved as we discovered the different reaction rates under different temperatures. The results are reliable, as we know enzymes do not work well when under extreme heat or denaturation occurs. What I learned in this experiment was that enzymes don’t work well under cold temperatures because they tend to move slower. My hypothesis did not quite match, because I thought they work best at lower temperatures.
Background and Introduction: Enzymes are proteins that process substrates, which is the chemical molecule that enzymes work on to make products. Enzyme purpose is to increase the rate of activity and speed up chemical reaction in a form of biological catalysts. The enzymes specialize in lowering the activation energy to start the process. Enzymes are very specific in their process, each substrate is designed to fit with a specific substrate and the enzyme and substrate link at the active site. The binding of a substrate to the active site of an enzyme is a very specific interaction. Active sites are clefts or grooves on the surface of an enzyme, usually composed of amino acids from different parts of the polypeptide chain that are brought together in the tertiary structure of the folded protein. Substrates initially bind to the active site by noncovalent interactions, including hydrogen bonds, ionic bonds, and hydrophobic interactions. Once a substrate is bound to the active site of an enzyme, multiple mechanisms can accelerate its conversion to the product of the reaction. But sometimes, these enzymes fail or succeed to increase the rate of action because of various factors that limit the action. These factors can be known as temperature, acidity levels (pH), enzyme and/or substrate concentration, etc. In this experiment, it will be tested how much of an effect
As stated in the introduction, three conditions that may affect enzyme activity are salinity, temperature, and pH. In experiment two, we explored how temperature can affect enzymatic activity. Since most enzymes function best at their optimum temperature or room temperature, it was expected that the best reaction is in this environment. The higher the temperature that faster the reaction unless the enzyme is denatured because it is too hot. Similarly, pH and salinity can affect enzyme activity.
Enzymes are specific-type proteins that act as a catalyst by lowering the activation energy of a reaction. Each enzyme binds closely to the substrate; this greatly increases the reaction rate of the bounded substrate. Amylase enzyme, just like any other enzyme, has an optimum PH and temperature range in which it is most active, and in which the substrate binds most easily.
Organisms cannot rely entirely on spontaneous reactions to produce all the materials necessary for life. These reactions occur much too slowly. To produce these materials quicker, cells rely on enzymes, biological catalysts, to speed up these reactions without being consumed. (General Biology I, Martineau, Dean, Gilliland, & Soderstrom, Lab Manual, 2017, 43). To produce these materials quicker, the activation reaction much be lowered, a very important part of this lab. Each enzyme acts on a specific molecule, or set of molecules, called a substrate (43). The enzyme binds to this substrate, forming an enzyme-substrate complex. An enzyme is a protein whose structure is determined by the sequence of amino acids groups that
An enzyme is a biological catalyst that speeds up the rate of reaction in certain biological functions. They play a vital role in many aspects of human physiology and are necessary for the functioning of a number of systems, for example in the digestive system to help to break down food. All enzymes have a unique active site that can fit on to a particular molecular arrangement on a target substrate; a substance e.g. carbohydrate, protein, or fat, that the enzyme is designed to breakdown. There are a number of different enzymes in the human body; each type produced specifically to perform a certain role. Enzymes are not themselves destroyed in the reaction to break down a
Alka-Seltzer contains both baking soda (NaHCO3) and citric acid (H3C6H5O7). The reaction between the bicarbonate ion and citric acid produces water, carbon dioxide, and the citrate ion. Equation 1 shows the balanced equation for the reaction, which can be expressed by, C_6 H_8 O_7 (aq)+ 3NaHCO_3 (aq)→ 3H_2 O(l) + 3CO_2 (g) + Na_3 C_6 H_5 O_7 (aq) (1)
The Effect of low pH on Enzyme Activity Frank Keith Welsh, BIO 102, Fall semester Today I will be providing an experiment on the effects of pH on enzymes. Enzymes are affected by changes in pH. Exceptionally high or low pH values commonly cause in complete loss of activity for most enzymes. Furthermore to include temperature and pH there are other elements, such as ionic strength, that can shake the enzymatic reaction. To each of these both physical and chemical parameters should be considered and optimized for an enzymatic reaction to be precise.
In the following experiments we will measure precise amounts of potato extract as well as Phenylthiourea, combined with or without deionized water and in some instances change the temperature and observe and record the reaction. We will also investigate the different levels of prepared pH on varying samples of the potato extract and the Phenylthiourea and record the results. We will answer question such as what is the best temperature for optimum temperature reaction as well as the best pH level for the same reaction.
An enzyme is a catalyst. Catalysts are known for speeding up the rate of reactions by lowering the activation energy of the biochemical reaction. (Reece et al., 2011)
generally act as a catalase that initially bring about a chemical reaction.” Enzymes play an
The purpose of this lab report is to investigate the effect of substrate concentration on enzyme activity as tested with the enzyme catalase and the substrate hydrogen peroxide at several concentrations to produce oxygen. It was assumed that an increase in hydrogen peroxide concentration would decrease the amount of time the paper circle with the enzyme catalase present on it, sowing an increase in enzyme activity. Therefore it can be hypothesised that there would be an effect on catalase activity from the increase in hydrogen peroxide concentration measured in time for the paper circle to ride to the top of the solution.
Enzymes, proteins that act as catalysts, are the most important type of protein[1]. Catalysts speed up chemical reactions and can go without being used up or changed [3] Without enzymes, the biochemical reactions that take place will react too slowly to keep up with the metabolic needs and the life functions of organisms. Catecholase is a reaction between oxygen and catechol [2]. In the presence of oxygen, the removal of two hydrogen atoms oxidizes the compound catechol, as a result of the formation of water [2]. Oxygen is reduced by the addition of two hydrogen atoms, which also forms water, after catechol is