Transketolase is an essential component of many enzymatic, biochemical processes. According to the National Center of Biotechnology Information, in conjunction with a self-paraphrased definition, transketolase is a thiamine pyrophosphate, metabolic coenzyme which is partly responsible for various catalytic reactions, sucrose breakdowns and chemical, ketose transports. Albert L. Lehninger, Michael Cox and David R. Nelson, the authors of Lehninger Principles of Biochemistry, confirm this proposed definition in the works of their book (2005). Transketolase functions in two general areas of interest: the carbon-reactions pathway (in plants, formerly referred to as the “Calvin cycle”) and the pentose phosphate pathway (in, both, plants and animals). …show more content…
“Transketolase,” as is, is just a general form of the word – almost a standard. There are several families and sub-families. To give a standard of transketolase’s presence in humans, let us look at specifics. Transketolase (TK or TKT) is assigned the number, 2.2.1.1., by the Enzyme Commission (EC). As a part but not limited to, it functions in homo-sapiens or humans (though there are species which only function in plant life as well). Transketolase has a complete protein sequence length of 623 AA. Within the cell, specifically, TK is located in the nucleus and cytosol. Understanding transketolase’s function is quintessential. Its function is the “catalyzation of the transfer of a two-carbon ketol group from a ketose donor to an aldose acceptor, via a covalent intermediate with the cofactor thiamine pyrophosphate (Universal Protein Resource, Transketolase, 2002-2014).” The total length of the protein chain goes from amino acid #1 to #623. However, one of the more important regions is from 123 through 125, where nucleotide binding occurs. This region is three amino acids in length and is comprised of thiamine pyrophosphate. Also, the proton donor is #366 in the protein sequence. Transketolase is more detail than is commonly …show more content…
Some important AA sites within the protein sequence are: 431 – which is one amino acid in length, a proton donor and a binding site for thiamine pyrophosphate; 167 – which is one amino acid in length and a metal binding site; 197 – which is one amino acid in length and a binding site for, both, magnesium and thiamine pyrophosphate; 76 and 459 – which are, both, one amino acid in length and binding sites for thiamine pyrophosphate; 273 – which is one amino acid in length, a binding site for thiamine pyrophosphate and an essential site for catalytic activity; and 126 through 128 – which, altogether, comprise three amino acids in length and are the sites for nucleotide binding of thiamine pyrophosphate. The actual sequence’s chain begins at 2 and ends at 706 (Sakai et al, 1998); the first in the sequence (“1”) is removed as the methionine initiator. However, the “family tree”
Living organisms undergo chemical reactions with the help of unique proteins known as enzymes. Enzymes significantly assist in these processes by accelerating the rate of reaction in order to maintain life in the organism. Without enzymes, an organism would not be able to survive as long, because its chemical reactions would be too slow to prolong life. The properties and functions of enzymes during chemical reactions can help analyze the activity of the specific enzyme catalase, which can be found in bovine liver and yeast. Our hypothesis regarding enzyme activity is that the aspects of biology and environmental factors contribute to the different enzyme activities between bovine liver and yeast.
Catalase is a common enzyme that is produced in all living organisms. All living organisms are made up of cells and within the cells, enzymes function to increase the rate of chemical reactions. Enzymes function to create the same reactions using a lower amount of energy. The reactions of catalase play an important role to life, for example, it breaks down hydrogen peroxide into oxygen and water. Our group developed an experiment to test the rate of reaction of catalase in whole carrots and pinto beans with various concentrations of hydrogen peroxide. Almost all enzymes are proteins and proteins are made up of amino acids. The areas within an enzyme speed up the chemical reactions which are known as the active sites, and are also where the
Finally, the last part of the experiment examined the enzyme activity at different pH levels. Four sets of 11 tubes were set up in this part. The procedure for this part is the same as before, but 4 other buffers were substituted for the standard pH 7.3 phosphate buffer. Set A used the 5.5 pH buffer while set B used the 6.5 pH buffer. The buffer of pH 8.5 was used for set B and for set D the pH was 9. The absorbance readings for 4 sets were taken and recorded in table 13. Using the linear equation that the best-fit line gave for each set, the Km and the Vmax of each set were determined. Then, table 15 was made by dividing the Vmax by the Km. of the four pHs. The Vmax and Km of the control set were also used to make
Mader, S. S. (2010). Metabolism: Energy and Enzymes. In K. G. Lyle-Ippolito, & A. T. Storfer (Ed.), Inquiry into life (13th ed., pp. 105-107). Princeton, N.J: McGraw Hill.
Abstract: Enzymes are catalysts therefore we can state that they work to start a reaction or speed it up. The chemical transformed due to the enzyme (catalase) is known as the substrate. In this lab the chemical used was hydrogen peroxide because it can be broken down by catalase. The substrate in this lab would be hydrogen peroxide and the enzymes used will be catalase which is found in both potatoes and liver. This substrate will fill the active sites on the enzyme and the reaction will vary based on the concentration of both and the different factors in the experiment. Students placed either liver or potatoes in test tubes with the substrate and observed them at different temperatures as well as with different concentrations of the substrate. Upon reviewing observations, it can be concluded that liver contains the greater amount of catalase as its rates of reaction were greater than that of the potato.
== Amylase is an enzyme found in our bodies, which digest starch into
Proteins are one of the main building blocks of the body. They are required for the structure, function, and regulation of the body’s tissues and organs. Even smaller units create proteins; these are called amino acids. There are twenty different types of amino acids, and all twenty are configured in many different chains and sequences, producing differing protein structures and functions. An enzyme is a specialized protein that participates in chemical reactions where they serve as catalysts to speed up said reactions, or reduce the energy of activation, noted as Ea (Mader & Windelspecht).
Alkaline Phosphatase (APase) is an important enzyme in pre-diagnostic treatments making it an intensely studied enzyme. In order to fully understand the biochemical properties of enzymes, a kinetic explanation is essential. The kinetic assessment allows for a mechanism on how the enzyme functions. The experiment performed outlines the kinetic assessment for the purification of APase, which was purified in latter experiments through the lysis of E.coli’s bacterial cell wall. This kinetic experiment exploits the catalytic process of APase; APase catalyzes a hydrolysis reaction to produce an inorganic phosphate and alcohol via an intermediate complex.1 Using the Michaelis-Menton model for kinetic characteristics, the kinetic values of APase were found by evaluating the enzymatic rate using a paranitrophenyl phosphate (PNPP) substrate. This model uses an equation to describe enzymatic rates, by relating the
Ketosis means our bodies are using fat for energy. Ketones (also called ketone bodies) are molecules generated during fat metabolism. Most of the fats our bodies break down for energy is converted into ATP, which is the “energy molecule.” Ketones are produced as part of the process. When people eat fewer carbohydrates, more ketones are generated. Some of these ketones (acetoacetate and B-hydroxybutyrate) are used for energy; the heart muscle and kidneys prefer ketones to glucose. Most of the cells in the body can use ketones as part of their energy. However, this is not true for acetone which cannot be used, and is excreted as waste mostly in the urine and breath. Sometimes a metabolic condition develops that causes a distinct odor in the breath. If there is enough acetone in the urine which can be detected with a Ketostix, this detection in the urine is called “ketosis.” Another metabolic condition is Ketoacidosis which can develop in people with Type 1 diabetes which may be confused with normal ketosis. (lowcarbdiet.about.com)
Various methods such as x-ray crystallography, NMR, and site-directed mutagenesis are applied to study how AP structure contributes to its function and how cofactors and amino acid residues affect reaction mechanism. Enzymes that retain similar structure and function to E. coli AP are found in other species and organisms. For instance, the physiological functions of human AP are still not known at present, but the level of alkaline phosphatase in bloodstream can be a valuable indicator to diagnose liver and bone diseases. Also, mutation in structural gene of human AP will result in hypophosphatasia, a metabolic disease that interfere with uptake of phosphorus and calcium. Thus, understanding the functions of metal ions and reaction mechanism of E. coli AP will provide a general insight of how other enzymes work and discover future potential use of AP in different areas of research or clinical
This lab attempted to find the rate at which Carbon dioxide is produced when five different test solutions: glycine, sucrose, galactose, water, and glucose were separately mixed with a yeast solution to produce fermentation, a process cells undergo. Fermentation is a major way by which a living cell can obtain energy. By measuring the carbon dioxide released by the test solutions, it could be determined which food source allows a living cell to obtain energy. The focus of the research was to determine which test solution would release the Carbon Dioxide by-product the quickest, by the addition of the yeast solution. The best results came from galactose, which produced .170 ml/minute of carbon dioxide. Followed by glucose, this produced .014 ml/minute; finally, sucrose which produced .012ml/minute of Carbon Dioxide. The test solutions water and glycine did not release Carbon Dioxide because they were not a food source for yeast. The results suggest that sugars are very good energy sources for a cell where amino acid, Glycine, is not.
The lac operon is a transcriptional control of lactose metabolism in bacteria. The operon contains three transcriptional genes, lac Z, lac Y and lac A, which encodes for β-galactosidase, permease and transacetylase respectively. Lac P and lac O copes for the lac promoter and the lac operator, essential to the functioning of this operon. β-galactosidase converts lactose to allolatose, while permease allow lactose to be transported into the cell. Transacetylase does not have a role in lactose usage. In the absence of lactose, there is no allolactose, converted from lactose by β-galactosidase, to the active regulatory repressor, and thus the repressor binds to the operator and transcription is inhibited, as the RNA polymerase bound to the promoter is blocked. In the presence of lactose, allolactose binds to the repressor, rendering it inactive and unable to bind to the operator, allowing the transcription of the three structural genes.
An enzyme is often known as biological catalysts. It acts a substance which speeds up the rate of a chemical reaction but remains unchanged through the process. It works by lowering the activation energy (the amount of energy required to initiate a chemical change) required for a reaction. Enzymes are proteins that are vital to the body because they act as effective catalysts and play an important role within body cells. Enzymes are proteins that are folded into a complex three-dimensional shape that contains an active site where the specific substrate binds structurally and chemically. There are four main protein structures: primary, secondary, tertiary, and quaternary. A primary structure consists of a linear strand of amino acids in a polypeptide chain. They are bonded to one another through covalent peptide bonds. Secondary structures are in coils and folds due to the hydrogen bonds present between hydrogen and oxygen atoms near the peptide bonds. Tertiary structures take a three-dimensional form due to the interaction between amino acids functional groups and disulfide bonds. ...
The N-terminal domain aids in formation of the dimer and anchoring the protein to the ribosomes whereas the C-terminal domain binds to EF-Tu in the ternary complex (Savelsbergh et al., 2000). Figure 11 -. L7/L12. The 50S subunit rRNA is depicted in gray and the 50S r-proteins are shown in cyan. The L12 dimers are shown in red with their CTD, NTD and the hinge region. The L10 that provides flexibility is shown in blue, while the L11 acting as an anchor is shown in yellow.
Grinde, Bjørn, and Grete Grindal Patil. "Abstract." National Center for Biotechnology Information. U.S. National Library of Medicine, 31 Aug. 2009. Web. 11 Apr. 2014.