What is Lowry's Method in Biochemistry?
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The Lowry Method\nThe Lowry method for determining protein concentration\nis essentially a biuret reaction that incorporates\nthe use of Folin-Ciocalteu reagent for\nenhanced color development. The Lowry procedure\nis more commonly used in research applications\nbecause it is ten times more sensitive than\nthe biuret reaction. In the Lowry method, protein is\nfirst treated with alkaline copper sulfate in the\npresence of tartrate. This “incubation” is then followed\nby addition of the Folin-phenol reagent. It is\nbelieved that the enhancement of the color reaction\nin the Lowry procedure occurs when the tetradentate\ncopper complexes transfer electrons to the\nphospho-molybdic/phosphotungstic acid complex\n(Mo+6/W+6, Folin phenol reagent). Reduction of the\nFolin phenol reagent yields a blue color read at 750\nnm.17,18\nAlthough the Lowry method has the distinction of\nbeing the most referenced assay in the biochemical\nliterature and has become the standard for protein\nquantitation, it is also well known for its deficiencies.\nFor example, the alkaline copper reagent\nis unstable and requires daily preparation with a\nmulti-step procedure that is time- and labor-intensive.\nIn addition, the assay has been shown to be\nphotosensitive. As a practical matter, precautions\nReferences\n4. Peterson, G.L. (1977). A simplification of the protein assay method of Lowry et.al. which is more generally applicable. Anal. Biochem. 83, 346-356.\n5. Schacterle, G.R. and Pollack, R.L. (1973). A simplified method for the quantitative assay of small amounts of protein in biologic material. Anal. Biochem.\n51, 654-655.\n6. Hartree, E.E. (1972). Determination of protein; A modification of the Lowry method that gives a linear photometric response. Anal. Biochem. 48, 422-427.\n17. Creighton, T.E. (1984). Chemical nature of polypeptides, in Proteins. New York: W.H. Freeman and Co., pp 1-60.\n18. Sengupta, S. and Chattopadhyay, M.K. (1993). Lowry’s method of protein estimation: some insights. J. Pharm. Pharmacol. 45, 80.\n19. Lo, C. and Stelson, H. (1972). Interference by polysucrose in protein determination by the Lowry method. Anal. Biochem. 45, 331-336.\n20. Neurath, A.R. (1966). Interference of sodium ethylenediaminetetraacetate in the determination of proteins and its elimination. Experientia 22, 290.\n21. Kuno, H. and Kihara, H.K. (1967). Simple microassay of protein with membrane filter. Nature 215, 974-975.\n22. Morrissey, T.B. and Woltering, E.A. (1989). Sodium oxalate corrects calcium interference in Lowry protein assay. J. Surg. Res. 47(3), 273-275.\n23. Sargent, M.G. (1987). Fiftyfold amplification of the Lowry protein assay. Anal. Biochem. 163(2), 476-481.\n26. Dawson, J.M. and Heatlie, P.L. (1984). Lowry method of protein quantification: evidence for photosensitivity. Anal. Biochem. 140(2), 391-393.\n27. Fryer, H.J.L., Davis, G.E., Manthorpe, M. and Varon, S. (1986). Lowry protein assay using an automatic microtiter plate spectrophotometer. Anal.\nBiochem. 153(2), 262-266.\nshould be taken to subject the samples to the same\nlevel of illumination during the procedure.26\nSeveral modifications of the original Lowry procedure\nhave been reported. For example, modifications\nhave been made to simplify the procedure4,5\nand to improve the following: linearity of response;\n6 reproducibility and sensitivity;23 stability\nand chemistry of color development; stability of\nthe biuret reagent;2,5 and speed.27 Other modifications\nhave dealt with interfering substances7 and\napproaches to the analysis of protein samples in\nthe presence of biomaterials such as lipids.\nMuch has been published regarding substances\nthat interfere with protein determination using the\nLowry procedure. Compounds commonly known\nto interfere with the Lowry assay include: detergents\nand carbohydrates;8,19 glycerol, Tricine and\nEDTA;20 Tris;21 potassium and sulfhydryl and disulfide\ncontaining compounds;9 magnesium;21 and\ncalcium.22\nThe addition of oxalate to
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The Bronsted Lowry Theory of acids and bases is the receiving (base) or the donating (acid) of a "proton" - in effect a Hydrogen ion H+\n\nThe Bronsted-Lowry definition is named for Johannes Bronsted and Thomas Lowry, who independently proposed it in 1923. A Bronsted-Lowry (BL) acid is defined as any substance that can donate a hydrogen ion (proton) and a Bronsted-Lowry base is any substance that can accept a hydrogen ion (proton). Thus, according to the BL definition, acids and bases must come in what is called conjugate pairs. \n\nFor example, consider acetic acid dissolved in water: \n\nCH3COOH (l) + H2O (l) <=> CH3COO-(aq) + H3O+(aq)\n\nBL acid       BL Base     Conjugate base  Conjugate Acid\n\nThe presence of H3O+(aq) in concentrations greater than OH-(aq) is characteristic of a solution (in water) which has a pH less than 7 when you are dealing with normal acid-base theory\n\nBronsted Lowry does not consider the concentrations of either; simply the transfer of the H+.\n\nCheck the link for more info - it is easier to read and a good explanantion
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Gel Electrophoresis is a biggie\nYou can take advantage of their isoelectric points\nYou can take advantage of their acid/base chemistry \nYou can selectiviely stain them (ninhydrin comes to mind)
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I dont know if this will help but here is a web site I found!\n\nhttp://www.biochemj.org/bj/119/0017/1190017.pdf
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Too many to list and explain here, without copying and pasting  --and why should I do all your uni work for you? ;-)\n\nI will recommend a couple of good text books through.  Well worth a purchase or just get them on loan from your library...\n\nAlberts et al, Molecular Biology of the Cell\nStryer, Biochemistry\n\nIt's been since I bought mine.  Think I got editions 2 & 7 back in 1996 and I know both have been updated a couple of times since.  These are still a GREAT basic resourse for this sort of question.
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You can measure it in a number of ways depending on the protein.\n\n-- pH may vary directly with concentration\n-- optical rotation measurements may work for some\n-- adding a dye to the protein and reading on a colorimeter\n-- Another way would be to degrade or react the protein in solution and then to measure the byproducts of the degradation/reaction by something as simple as a titration
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A bit vague but a you could work out the rate from a titration, also the molar value from the same experiment.
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The current way would be ion chromatography.  There are older less reliable methods.  You test for the calcium separate form the anions.  The calcium can also be donw by ICP or AA.
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use the equation  pH= -lgKa+ lg( salt/acid)\n(this equation only applies for buffer system)
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Prozymes (protein portion of the enzyme) require a spacific temperature range to operate properly.  At both ends of this spacific operating range there are laten temperature ranges.  These ranges render the prozyme ineffective but still redeemible. Even further from the spacific temp range, outside the laten temp ranges are denaturation temps.  These are the temps where the prozyme is damaged to the point where it can never again function properly.  The heating methode of denaturation is usually used only when pH of the resulting supernatant will be measured.  Otherwise one could simplely titrate to the desired pH using a more effective methode. \n\nAs not to disperce the debriss of denaturation into your solution the Acid coagulum methode is perhaps the best way.  This can be achieved by adding to the solution just enough glaceral acitic acid untill the protein stops gelling.  The solution should actually become less turbit.  Finally, use ETOH to counter titrate to the desired pH.  Remember countertitration makes water (H2O) in your solution so don't add excessive acid to begin with. E-mail me with your results.  I am interested.
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Well... A titration is a method to know an unknown concentration of a given solution.\nIf you need to know a NaOH solution concentration, you should do the following:\n1. Measure 20 ml of NaOH.\n2. Drop some drops of phenolphtalein (10 should do, no more)\n3. The solution will go pink with this drops of phenolphtalein...\n4. Using a burette (it's a graduated tube to know how much of a given substance you are pouring), drop some HCl (you should have this in your laboratory) measuring it till the solution of NaOH is clear again.\n5. Solve this equation: V(HCl) x N(HCl) = V(NaOH) x N(NaOH)... V(HCl) it's the volume you used to turn the solution clear again. The N(HCl) it's the concentration of that HCl (Chloridric Acid) given in equivalents/litre. V(NaOH) is 20 ml, the one you used at the begining... You have to calculate N(NaOH), and that's it =)\nHope you find it useful! ^^
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use spectrophotometric method(uv-vis spectrometry).Few things u shud remember.....\n1) Use Labert-Beer's law\n2) u shud know the molar extingtion coefficient value of that particular species\n3) concentration of the species\n4) Calculate lambdamax. using LB law\nIt is an indirect method.\n\nUV-VIS. Spectroscopy will give u the lambdamax value directly...alongwith absorbance
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G.W. Jr. Shipps, U.P. Spitz, J. Jr. Rebek, Solution-Phase Generation of Tetraurea Libraries, Bioorganic & Medicinal Chemistry \nfound at the site... \nhttp://www1.elsevier.com/cdweb/journals/09680896/viewer.htt?viewtype=keywords&rangeselected=32\n\nlooks like fun stuff :) don't inhale
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Try it out in the lewis-dot diagram\n      ..        ..\nH-O-Ca-O-H\n      ..        ..
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See comment above.\n\nYou do need to do several trials at various concentrations though. You can then determine it through a linear regression.\n\nI also suggest that you consult a book on Analytical chemistry, because Beer's law has limitations. For example, it loses linearity at higher concentrations.
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carwash's ideas are pretty good, particularly TLC and spectroscopy.\n\nI don't think I'd do a titration against a base, because esters will also react with bases (hydrolysis). For a synthesis, this doesn't matter. But for an analytical method, it invalidates the technique, unless you can account for it with a standard or something. You might end up getting a result higher than what it should be because of it. (It depends on the chemical environment of the ester)
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The answer should be Hydrolysis.