New answers tagged biochemistry
1
In the United States, sucralose is sold under the brand Splenda. There is a liquid product with the food label shown below:
The low calorie sweeteners containing sucralose come in different form, and they often contain sugars with calories. Here is one example:
It contains glucose as the main ingredient. Nevertheless, they are allowed to say it is suitable ...
-1
The test is based on imine formation. The formation of imine from carbonyl compound occurs in equilibrium ergo the principle of le Chatelier is applicable to the test. According to this principle the increase of the concentration of at least one of the products results in the decrease of degree of conversion of the reactant.
I guess that you are trying to ...
-2
http://guweb2.gonzaga.edu/faculty/cronk/CHEM440pub/thioesters.html
"thioester cannot make as much of a contribution because the required overlap between carbon's 2p orbital and the sulfur 3p orbital is ineffective. The large difference in energy between these two orbitals means they cannot "mix" as well as the 2p orbitals of oxygen and carbon."
2
The good mnemonic tool to remember is :
Anode = anabasis, electrons would be going upwards from the electrode to the wire = oxidation, ( Xenophon, Anabasis, 404BC, "The journey upwards(to north))
Cathode = cathabasis(the journey downwards), electrons would be going downwards from the wire to the electrode = reduction
That means a cathode/anode is the ...
5
Who was responsible for this naming system and how can we change it?
Michael Faraday was responsible for the terms anode and cathode more than hundred years ago.
All the confusion regarding the nomenclature will vanish if you do not associate electrostatic signs with these two terms. One should identify the electrode labels with the redox processes rather ...
3
I think you are simply misunderstanding the "uncharged to charged" part of the question. Imidazole is a base, so it gains a proton to become charged when the pH < pKa. That's why you got the right answer when you used $\ce{HA+}$ as the acid, as you put it. In this case, unlike with most general chemistry problems of this nature, the acid is charged while ...
2
The answer given by @M. Farooq may be interpreted as «the optimization of TLC depends on the choice of the eluents used, which till now (by broader advent of machine learning) was empirical».
In my opinion, this should not the impression to retain. Of course the optimization of TLC depends 1) on the eluent / eluent mixture, but should be seen in context of ...
2
I can give a very pictorial answer that doesn't require the use of actual pictures nor typesetting and might useful for beginners.
It is all about the misconception, encountered even in chemists with a relative experience in successful experiments, that solubility of the compounds in a mixture is a key factor for their effective chromatographic separation ...
5
Chromatography is really an empirical science. The fluid mechanical side and the adsorption phenomenon is somewhat well understood but choosing mobile phases is essentially based on trials, sadly to date. If someone has given you a ratio, say 8:2, it means someone must have tried it and they found that this mobile phase works the best. The main criterion for ...
2
Does the charge on the acidic and basic amino acids make them more polar and hydrophilic than the uncharged polar amino acids?
Yes, they are less likely to be on the inside of a protein. Hydrogen bonds with water will be stronger, and interactions with ions as well.
Moreover, cysteine is classified as an uncharged amino acid, but because it has an ...
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