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Related Concept Videos

Titration of a Polyprotic Acid02:08

Titration of a Polyprotic Acid

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A polyprotic acid contains more than one ionizable hydrogen and undergoes a stepwise ionization process.  If the acid dissociation constants of the ionizable protons differ sufficiently from each other, then the titration curve for such polyprotic acid generates a distinct equivalence point for each of its ionizable hydrogens. Therefore, titration of a diprotic acid results in the formation of two equivalence points, whereas the titration of a triprotic acid results in the formation of three...
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Acid-Base Titration Curves02:23

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A titration curve is a plot of some solution property versus the amount of added titrant. For acid-base titrations, solution pH is a useful property to monitor because it varies predictably with the solution composition and, therefore, may be used to monitor the titration’s progress and detect its endpoint. Acid-base titration can be performed with a strong acid and a strong base, a strong acid and a weak base, or a strong base and a weak acid.
For a titration carried out for 25.00 mL of...
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Microbial Growth Measurement: Direct Methods01:23

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Direct methods for measuring microbial populations in a culture are essential tools in microbiology, providing quantitative data for various applications. Among these, microscopic counts, plate counts, and serial dilution are widely used techniques, each with unique principles and applications.Microscopic CountsMicroscopic counting involves the use of a Petroff-Hausser chamber, a specialized microscope slide with a grid and defined depth. By observing a liquid culture under a microscope,...
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Microbial Growth Measurement: Indirect Methods01:27

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Estimating microbial growth is essential for understanding population dynamics and environmental adaptations. Indirect methods provide valuable insights by measuring parameters such as turbidity, metabolic activity, and biomass, enabling efficient and reproducible assessments.During exponential growth, microbial cells scatter light proportionally to their biomass, a principle used in turbidity measurements. About one million cells per milliliter produce detectable scattering, which a...
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The JAK-STAT Signaling Pathway01:20

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Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...
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Titration Calculations: Weak Acid - Strong Base03:55

Titration Calculations: Weak Acid - Strong Base

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Calculating pH for Titration Solutions: Weak Acid/Strong Base
For the titration of 25.00 mL of 0.100 M CH3CO2H with 0.100 M NaOH, the reaction can be represented as:
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Use of the Protease Fluorescent Detection Kit to Determine Protease Activity
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Measurement of Microbial Protease Activity Using a pH-Stat Titration.

H A Alkanhal1, J F Frank1, G L Christen1

  • 1Animal and Dairy Science Department, University of Georgia, Athens, Georgia 30602.

Journal of Food Protection
|April 5, 2019
PubMed
Summary
This summary is machine-generated.

The pH-stat titration method offers a more sensitive and efficient way to measure microbial protease activity compared to the TNBS method, especially for enzymes active at pH 9.

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Area of Science:

  • Enzymology
  • Microbiology
  • Biochemistry

Background:

  • Protease activity is crucial in various industrial and biological processes.
  • Accurate and sensitive measurement of protease activity is essential for research and development.
  • Existing methods like the trinitrobenzenesulfonic acid (TNBS) assay have limitations.

Purpose of the Study:

  • To compare the efficacy of the pH-stat titration method and the TNBS method for measuring microbial protease activity.
  • To evaluate the sensitivity, speed, and repeatability of both methods.
  • To determine the optimal method for proteases with varying pH activity profiles.

Main Methods:

  • Purified and crude microbial proteases were analyzed.
  • Activity was measured using an automatic pH-stat instrument at pH 9.
  • The pH-stat titration method was directly compared with the TNBS method.
  • Repeatability and linear correlation (R²=0.985) were assessed.

Main Results:

  • The pH-stat titration method yielded higher activity measurements than the TNBS method for purified Bacillus amyloliquefaciens protease.
  • Both methods showed excellent repeatability (C.V.=2.6%).
  • The pH-stat method demonstrated greater sensitivity and indicated higher proteolytic activity for Pseudomonas spp. with optimal activity at pH 9.

Conclusions:

  • The pH-stat titration method is simpler, faster, and more sensitive than the TNBS method for determining protease activity, particularly for enzymes with optimal activity at or above pH 9.
  • The pH-stat method provides a more accurate assessment of protease activity in certain microbial samples.
  • This finding has implications for optimizing enzyme assays in industrial and research settings.