plant bio lab exam notes

plant bio lab exam notes - PLANT BIOLOGY LAB EXAM REVIEW...

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P LANT B IOLOGY L AB E XAM R EVIEW N OTES : **Always write phylum and class with a capital letter in the beginning; know terms in dichotomous key; 3 life cycles and their differences. ** Lab 1: Objectives: - Measure and explain the effects of changes in temperature, pH, enzyme concentration, and substrate concentration up on the reaction rates of the catalase-catalyzed conversion of hydrogen peroxide to oxygen and water - Produce a standard curve and determine the protein content of a solution using that curve - Use a spectrophotometer - Explain how environmental factors affect the rate of enzyme-catalyzed reaction Notes/ Details of Lab: - Enzymes are biological catalysts; they speed up the reaction rates up to a factor of 10 14 o This is done by lowering the activation energy (even in low temperature, i.e. lower energy processes, catalysts succeed in lowering the activation energy thereby speeding up the reaction) - Enzymes proceed in the following way: o The enzyme binds to the reactant molecule (known as the substrate), initiating catalysis only when the three-dimensional conformation of the substrate is able to accommodate the enzyme o The substrate is subjected to the effects of the catalyst and are subsequently changed into products; once they are products the enzyme releases itself and binds to another reactant molecule Thus, one enzyme can catalyze many reactant molecules into products - All aspects of plant metabolism are involved with enzymes - Very important enzymatic reaction—reducing oxidative stress - For example, superoxide anion O 2 - can destroy plant chloroplast, mitochondria, endoplasmic reticulum… etc., catalyst that regulates this superoxide anion is superoxide dismutase, converting this superoxide anion to hydrogen peroxide o Hydrogen peroxide still quite toxic to cells; secondary line of defense is catalase (hydrogen peroxide oxidoereductase)—enzyme that breaks down hydrogen peroxide into water and oxygen Hydrogen peroxide oxidoreductase (catalase) is a haem-protein (i.e. one that contains iron) - Catalase is present in all aerobic eukaryotes; they act as both electron acceptors and donators to transform hydrogen peroxide into water and oxygen - Catalase also plays a role in plant defense: when being attacked by bacteria, fungi, or virus the plant communicates with other parts of the plant, warning the other plants of the plan about the attack. Those parts of the plant that have yet to be attacked then produce toxic radicals that murk the shit that’s trying to kill it. Communication is done via catalase - In this lab, we will determine enzyme purity of an extract using the Bradford method o The protein used in this lab is BSA (bovine serum albumin)—was selected because it provides a colour yield similar to one found in plants (even though its an animal enzyme); also, most standard proteins are of animal origin
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o The dye reagent used in this lab is Coomassie Brilliant G-250 because its chemical structure shifts when bound to proteins, thus being able to be read at 595 nm (the
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This note was uploaded on 02/21/2012 for the course BIO Bio2137 taught by Professor Namroud during the Fall '11 term at University of Ottawa.

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plant bio lab exam notes - PLANT BIOLOGY LAB EXAM REVIEW...

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