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2-mercaptoethanol (2ME) reduces the disulphide bonds in proteins. If disulphide bonds are connecting two polypeptide chains ("intermolecular") then 2ME would cause them to separate and therefore instead of a higher molecular weight (MW) band you would get one or more lower MW bands. However, if there are disulphide bonds in the same polypeptide chain, they ...


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The mechanical stability of a protein (I am assuming by strength you mean mechanical stability) depends greatly on the general context and there is no clear connection between alpha helix or beta-sheet content and stability. For example fibroin, one of the main components of spider silk and one of the strongest proteins known, consists mainly of beta sheets ...


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It is not strictly required. Isotope labelling is required when the usual isotope does not have a magnetic spin (for example 12C). 14N has a spin of 1 and exhibits 3 spin states: -1, 0 and 1. The isotope, 15N has a 1/2 spin. As noted in this book, analytical methods exist for both nitrogen isotopes. However, 15N is preferred for NMR studies because the ...


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I would add this as a comment to your question but do not have enough reputation. A simple look at Wikipedia (which is a very good source for general questions like these) would have provided you with an answer. I just did this to see how long it would take if I did not know the answer. It was about 20-30 seconds. Protein synthesis: Transcription In ...


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The Atkins diet is based on that. Without carb intake, however, the citric acid cycle (CAC) eventually basically stops and proteins will be utilized to be converted to carb intermediates to feed the CAC. Progressive and strict use of the Atkins diet will eventually kill you as the CAC is essential to life. The idea behind Atkins is that fats will be used ...


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No, the search won't be less reliable. It will only be more sensitive, more capable of finding matches. To understand this, you need to understand how the BLAST algorithm works, what the word size means. When you use a word size of $N$, BLAST starts by looking for a match of length $N$ between your query and target sequences. If such a match is found, ...


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X-ray crystallography has been used to detect phosphorylated sites. The RCSB protein database currently contains 856 structures that have both a resolution below 3 angstroms and the keyword "phosphorylated" in their listing. It also appears to be possible to use NMR to study phosphorylated proteins. The situations where NMR/x-ray crystallography or ...


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There is a difference between animals in their requirements for amino acids. For example, cats need high amounts of taurine (and can't make it) and when fed diets lacking enough can go blind. This is why vegans trying to feed vegan diets to their pets can be very bad for the pet. Animal proteins have sufficient taurine for the cat. However, the meat of a ...


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One way of examining this is by looking at the transcriptome as a whole before and after the introduction of the chemical. I would use microarray or next generation sequencing RNA-seq technology to look on the expression level of all the genes after the introduction of the chemical, some inert control and no treatment control. Then, you can calculate the ...


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Welcome to Biology.SE The question suggests that you have important lack of knowledge in Biology (which is fine). It will be impossible to explain everything in a post. I therefore just provide a short answer and redirect you to some source of knowledge that will be necessary to read for you to really be able to understand the basis of molecular biology and ...


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You ask initially about the “sense” and “antisense” strands of DNA. These terms are explained in the Wikipedia reference entitled ‘Sense strand’. This states what you appear to be already aware of, that: “The sense strand is the strand of DNA that has the same sequence as the mRNA, which takes the antisense strand as its template during transcription…” ...


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I believe the OP is referring to an old and outdated system of classification, in which all proteins are polypeptides but not all polypeptides are proteins: some books put a lower limit of 50 AA residues, others talked about 60 or 70 AA for a polypeptide being considered a protein. Once again, this system is no longer used (just check Lehninger, "Principles ...


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Your instinct is valid, there are other molecules which can be defined as having tertiary structure. The most common example is RNA, which can fold into a vast array of conformations. These can be part of ribonucleoprotein complexes like telomerases, spliceosomes, or ribosomes or they can function on their own like tRNAs and many ribozymes such as RNase P. ...


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Looking at the documentation you provide, I think that I can provide definitions for those terms as defined by EXPASY. Note that those definitions may just be an in-house system that EXPASY uses that you can't generalize to other databases for instance. First, in section I.C of the documentation, they write "The use of protein sequence patterns (or motifs) ...


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In the biological context, membrane-partitioning is usually referring to the stage in which the transmembrane-destined region of a protein moves from interacting with the water, to interact with the interface of the membrane. In the diagram below showing a four step thermodynamic cycle, the partitioning free energy can be referred to as as ΔGwiu in terms ...


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Ferredoxins and variants such as fladidoxins and rubredoxins are simply electron carrying protein that need to be regenerated, like the more energetic NADPH. The key thing to remember is that redox balance is key. You cannot have electron pair accumulate so there has to be a terminal acceptor. In the case of aerobic resipration it is oxygen, in the case of ...



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