An Interactive Classroom Activity Demonstrating Reaction Mechanisms and Rate-Determining Steps

2005 ◽  
Vol 82 (4) ◽  
pp. 549 ◽  
Author(s):  
Laura D. Jennings ◽  
Steven W. Keller
2019 ◽  
Vol 9 (11) ◽  
pp. 2794-2805 ◽  
Author(s):  
Kuber Singh Rawat ◽  
Shyama Charan Mandal ◽  
Preeti Bhauriyal ◽  
Priyanka Garg ◽  
Biswarup Pathak

Understanding the product selectivity, conversion, and rate-determining steps in the catalytic upgrading of ethanol to butanol.


2014 ◽  
Vol 76 (6) ◽  
pp. 396-401 ◽  
Author(s):  
Bethany Bowling ◽  
Erin Zimmer ◽  
Robert E. Pyatt

Although the development of next-generation (NextGen) sequencing technologies has revolutionized genomic research and medicine, the incorporation of these topics into the classroom is challenging, given an implied high degree of technical complexity. We developed an easy-to-implement, interactive classroom activity investigating the similarities and differences between current sequencing methodology and three NextGen technologies. The activity uses existing materials created by each of the biotechnology companies that outline their instrumentation and chemistries. Following this activity, students will understand the molecular biology behind these NextGen applications and the similarities to existing Sanger sequencing methods.


2008 ◽  
Vol 6 (2) ◽  
pp. 305-311 ◽  
Author(s):  
Alan F. Chow ◽  
John C. Howard ◽  
Nancy J. Lambe

Author(s):  
José Carlos Pinto ◽  
Marcos W. Lobao ◽  
Andre L. Alberton ◽  
Marcio Schwaab ◽  
Marcelo Embiruçu ◽  
...  

In this work, issues related to the mathematical modeling and statistical analyses of kinetic data are discussed. Firstly, problems related to the combinatorial explosion of the number of plausible kinetic models are analyzed, when complex reaction mechanisms are taken into consideration and distinct rate determining steps are assumed. Although modeling procedures based on rate-determining steps can lead to oversimplification of kinetic models, these procedures are still very popular because the existence of multiple rate-determining steps usually renders the analytical derivation of kinetic rate expressions impossible. However, if the derived kinetic models are too simple, one can face serious difficulties to fit the proposed models to available experimental data. Secondly, problems related to the statistical analyses of experimental data are discussed. Particularly, very often statistical tools are used even when some of the fundamental assumptions required for their validity are violated. For this reason, the fundamental grounds that support some of the most popular statistical tools are discussed in the framework of the kinetic analysis.


Author(s):  
Jeff Gelles

Mechanoenzymes are enzymes which use a chemical reaction to power directed movement along biological polymer. Such enzymes include the cytoskeletal motors (e.g., myosins, dyneins, and kinesins) as well as nucleic acid polymerases and helicases. A single catalytic turnover of a mechanoenzyme moves the enzyme molecule along the polymer a distance on the order of 10−9 m We have developed light microscope and digital image processing methods to detect and measure nanometer-scale motions driven by single mechanoenzyme molecules. These techniques enable one to monitor the occurrence of single reaction steps and to measure the lifetimes of reaction intermediates in individual enzyme molecules. This information can be used to elucidate reaction mechanisms and determine microscopic rate constants. Such an approach circumvents difficulties encountered in the use of traditional transient-state kinetics techniques to examine mechanoenzyme reaction mechanisms.


Author(s):  
A. Angel ◽  
K. Miller ◽  
V. Seybold ◽  
R. Kriebel

Localization of specific substances at the ultrastructural level is dependent on the introduction of chemicals which will complex and impart an electron density at specific reaction sites. Peroxidase-antiperoxidase(PAP) methods have been successfully applied at the electron microscopic level. The PAP complex is localized by addition of its substrate, hydrogen peroxide and an electron donor, usually diaminobenzidine(DAB). On oxidation, DAB forms an insoluble polymer which is able to chelate with osmium tetroxide becoming electron dense. Since verification of reactivity is visual, discrimination of reaction product from osmiophillic structures may be difficult. Recently, x-ray microanalysis has been applied to examine cytochemical reaction precipitates, their distribution in tissues, and to study cytochemical reaction mechanisms. For example, immunoreactive sites labelled with gold have been ascertained by means of x-ray microanalysis.


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