Succinate Dehydrogenase Lab Report

Succinate dehydrogenase is an enzyme of the tricarboxylic acid cycle and is found in mitochondria. Succinate dehydrogenase is very stable and is found at high concentration only in the mitochondrion of eukaryotes. It can be easily used as a marker enzyme for mitochondria and we used it to estimate the realative amounts of mitochondira in…Jacob and Monod used the lactose metabolism system of Escherichia Coli (E. Coli) to better understand the problem of enzyme induction, the occurrence of a particular enzyme only when its specific substrate is present. In the lac operon system, enzyme induction occurs when the presence of specific galactosides, also known as inducers, produce more than 1000 times as much of an enzyme -β-galactosidase, which
By following the fate of radioactively labeled amino acids added to growing cells either before or after the inclusion of the inducer, they found that induction symbolized the synthesis of new enzyme molecules. By applying kinetics to an experiment they were able to determine that these molecules could be detected as early as 3 minutes after the addition of an inducer. Likewise, removing an inducer caused a sudden stop in the synthesis of the new enzyme. Through Jacob and Monod’s work it was determined that the cell has a mechanism for turning gene expression on and off in response to environmental signs. HANS KREBS DISCOVERED THE SEQUENCE of reactions of the tricarboxylic acid cycle. Krebs determined how to accelerate the rate of oxygen consumption and pyruvate oxidation by adding specific dicarboxylic and tricarboxylic acids that stimulated the oxiation of pyruvate. Malonate, a succinate dehydrogenase inhibitor caused all intermediates to lose their effect on pyrucate oxidation. He determined that the oxidation of pyruvate was accomplished through a cyclic pathway and that pyruvate perforated the pathway by combining with oxaloacetate to form citrate with the production of
The way the DNA code is ordered is specific to the order of amino acids in a protein. The protein takes on a certain form when the gene is expressed and synthesizes the protein that it is coding for. When a protein is a specific shape it can carry out specialized functions, like catalyzing chemical reactions. Protein synthesis requires energy, so when an organism has the ability to control their genes and only switch them on when they enzyme they code for is needed. Lactose is found in milk and is not found in many other environments. If the gene for -β-galactoside was permanently switched on, it would be a waste of energy. Two scientists Jacob and Monod hypothesized Escherichia Coli (E. Coli) produces the enzyme -β-galactoside, this enzyme breaks apart lactose into glucose and galactose. The -β-galactosidase gene is typically switched off, except in the presence of lactose. The lac operon is a classic example of gene regulation, where the production of -β-galactosidase (lactase) is induced by the existence of lactose in the growth of the