Factors That Affect Enzyme Activity Essay

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

The temperature can have a major impact on an enzyme. According to Campbell Biology author Reece etc. 2011 “The enzyme reaction will increase as the temperature increase with the increasing temperature….substrates collide with active sites more frequently when the molecules move rapidly.”(Reece etc 2011) Every enzyme hits its optimal temperature the reaction will be at its highest point.(Reece etc. 2011) When the

Enzyme catalysis is dependant upon factors such as concentration of enzyme and substrate, temperature and pH. These factors determine the rate of reaction, and an increase in temperature or pH above the optimum will

pH - Enzymes also have an optimum pH level. The pH of a solution affects the enzyme's secondary and tertiary structures. These bonds make the shape of an enzyme's active site. So, if these bonds are broken, the shape of the active site changes and is distorted. If there is no active site, there is no reaction resulting in no products. If the enzyme is put in a pH that is very different from the optimum pH, it can cause the enzyme to denature.

Enzymes are types of proteins that work as a substance to help speed up a chemical reaction (Madar & Windelspecht, 104). There are three factors that help enzyme activity increase in speed. The three factors that speed up the activity of enzymes are concentration, an increase in temperature, and a preferred pH environment. Whether or not the reaction continues to move forward is not up to the enzyme, instead the reaction is dependent on a reaction’s free energy. These enzymatic reactions have reactants referred to as substrates. Enzymes do much more than create substrates; enzymes actually work with the substrate in a reaction (Madar &Windelspecht, 106). For reactions in a cell it is

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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.

Question: How does changing enzyme concentration or temperature affect the reaction time of enzyme activity?

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 defined as catalysts that speed up chemical reactions but remain the same themselves. The shape of an enzyme enables it to receive one type of molecule and that specific molecule will fit into the enzyme’s shape. Where a substance fits into an enzyme is called the active site and the substance that fits into the active site is called a substrate. Several factors affect enzymes and the rate of their reactions. Temperature, pH, enzyme concentration, substrate concentration, and the presence of any inhibitors or activators can all affect enzymes. Temperature can affect enzymes because if the temperature gets too high, it can cause the enzyme to denature. pH can affect an enzyme by changing the shape of the enzyme or the charge properties of the substrate so that either the substrate cannot bind to the active site or it cannot undergo catalysis. Every enzyme has an ideal pH that it will strive in. Increasing substrate concentration increases the rate of reaction because more substrate molecules will be interacting and colliding with enzyme molecules, so more product will be formed. Inhibitors can affect enzymes and the rate of their reactions by either slowing down or stopping catalysis. The three types of inhibitors include competitive, non-competitive, and substrate inhibition.

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

Enzymes are a key aspect in our everyday life and are a key to sustaining life. They are biological catalysts that help speed up the rate of reactions. They do this by lowering the activation energy of chemical reactions (Biology Department, 2011).

“Enzymes are proteins that have catalytic functions” [1], “that speed up or slow down reactions”[2], “indispensable to maintenance and activity of life”[1]. They are each very specific, and will only work when a particular substrate fits in their active site. An active site is “a region on the surface of an enzyme where the substrate binds, and where the reaction occurs”[2].

Enzymes are natural catalysts that work from the ability to increase the rate of reaction by decreasing the activation energy of a reaction. (Blanco, Blanco 2017) An enzyme can do this 10^8- to 10^10 fold, sometimes even 10^15 fold. (Malacinsk, Freifelder 1998) The substrate will momentarily bind with the enzyme making the enzyme-substrate complex, of which the shape of the substrate is complimentary to the shape of the active site on the enzyme it is binding with. There are two main theories as to how an enzymes and substrates interact, the lock-and-key model and induced fit theory. The lock-and-key model suggests that the enzyme has a specific shape that fits the substrate and only that substrate. The induced fit theory says the active site and substrate are able to change shape or distort for the reaction to take place with (Cooper,

Almost all enzymes need specific conditions for them to function. The conditions include temperature, pH level, and concentration of salt. Enzymes have optimal conditions. If they are changed, the enzyme may denature and deactivate. If that happens, the enzyme would not be able to catalyze the reaction, and the reaction rate would decrease (Worthington 2010).