I chose to do an experiment on ‘How temperature can affect the rate of enzyme activity in the liver?’ Temperature affects the “speeds of the molecules, the activation energy of the catalytic reaction and the thermal stability of the enzyme and substrate.” (2) At different levels of temperature the affects on the enzyme in the liver varies. The reason for this is because; “their molecules have low kinetic energy and collisions between them are less frequent.” (2) In other words at low temperatures, enzymes become ‘deactivated’. (2) Whereas on the other hand when the temperature is increased the activity that occurs in the
Effect of Enzyme Activity on Temperature Aim: The aim of this experiment is to investigate how effectively the enzyme amylase breaks down starch at different temperatures Research Question: How does the increase in temperature affect the time taken for amylase to breakdown 2ml of starch? Purpose: Background Information: Enzymes are biological catalysts that comprise the largest and most highly specialized class of protein molecules. Enzymes act as catalysts to increase the rates of chemical reactions. A fundamental property of enzymes is their specificity. Various enzymes have unique shape and chemical composition that creates a site, called and active site.
(Chem4kids, 2004) Before discussing the effects and uses of catalysts I should elaborate on what they are. A catalyst is a substance that lowers the activation energy of a chemical reaction. This lowered requirement allows more molecules to participate in a reaction at any given time, increasing the reaction rate. However catalysts are very specific and will only work with particular molecules. (See diagram right.)
Enzymes act as biological catalysts; they make chemical reactions to work quicker and remains unchanged when the reaction finishes. Therefore enzymes are used to speed up biological reactions in body. They can be working within cells and outside cells catalyzing metabolic reactions in human bodies. Enzymes are globular proteins; therefore they are soluble and easily transported in blood. Enzyme has an active site in a specific shape because of its tertiary structure.
Enzymes Activity i. Introduction: An enzyme is a compound that aids the chemical reaction within a cell by speeding up the rate at which it occurs. Most chemical reactions would occur too slowly for the cell to work properly without the enzyme. A metabolic reaction is any chemical change that occurs within a cell. Enzymes are proteins that are used to speed up these reactions without being consumed by them.
5. Describe how temperature and pH affect sucrase activity. Introduction Enzymes are usually protein molecules that act as biological catalysts. A catalyst greatly increases the speed of a chemical reaction by lowering the activation energy necessary to get the reaction started without itself being altered or consumed. On the surface of the enzyme is an active site that temporarily binds the reactants or substrates forming an enzyme-substrate complex.
Certain factors affect the rate of reaction:- Temperature – temperature increase the rate of reaction because the molecules gain kinetic energy and this increases the likelihood of an enzyme and a substrate colliding, subsequently increasing the rate of reaction. If this temperature goes over the optimum temperature then the active site of the enzyme will become denatured. The bonds that hold the enzyme together will be broken causing it to lose its 3-D structure, and substrate will no longer be able to fit , so no more E/S complexes will be formed. PH – Like temperature enzymes have an optimum PH. If the PH goes over the optimum PH then the chemical nature of the amino acids can alter.
Enzymes and temperature As the temperature increases, so does the rate of reaction, but very high temperatures denature enzymes. This graph shows how the rate of reaction changes due to increasing levels of heat. As the graph shows: at roughly 37ºC (body temperature) the rate of reaction starts to fall, and the rate falls rapidly as the enzyme is denatured. Enzymes and pH Like with heat, changes in pH levels can denature an enzyme, different enzymes work best at different pH levels. The pH level where the enzyme works best depends on where it is in the body.
Dependent Variable: The time taken in seconds the enzyme to react at different temperatures. This is because the temperature of the enzyme is reacting at will either make the enzyme reacts faster or slower. The rate of digestion will be calculated by 1/t (sec-1) Controlled Variables: concentration of enzyme (3 ml lipase) X nextag shop; Lipase Concentrate-HP 90 UltraCaps - Integrative Therapeutics; $24 (http://www.nextag.com/enzyme-lipase/compare-html) concentration of substrate (3 ml cooking oil) concentration of inhibitor (1 ml bile salt) All of these are fixed so that it does not affect the reaction. Introduction: Proteins that are made up of long chains of amino acids are called enzymes. These enzymes act as catalysts in chemical reactions which decreases the activation required for the reaction and consequently
Once these two components come together, certain chemical bonds within the substrate molecule change much as a lock is released, and just like the key in this illustration, the enzyme is free to execute its duty once again. Many chemical reactions do proceed but at such a slow rate that their progress would seem to be imperceptible at normally encountered environmental temperature. Consider for example, the oxidation of glucose or other sugars to useable energy by animals and plants. For a living organism to derive heat and other energy from sugar, the sugar must be oxidized (combined with oxygen) or metabolically "burned" However, in a living system, the oxidation of sugar must meet an additional condition; that oxidation of sugar must proceed essentially at normal body temperature. Obviously, sugar surrounded by sufficient oxygen would not oxidize very rapidly at this temperature.