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Everything posted by Maximilian

  1. Yup, that seems about what you'd expect under those conditions! I'm glad I could help.
  2. This question is hard to answer because it depends on how you decide to define a living thing, what cellular structures you are looking for, what you mean with genetic material, and what you mean with "basic feature". In my opinion, the answer to this question will change depending on who asks it. For example, if your professor is of the opinion that Viruses are not alive and you just went over viral genetics, then she might be looking for the answer "Cellular structure because viruses also contain genetic information and are not alive". However, perhaps your professor chose to define lif
  3. In general, organic molecules with no conjugated double bonds will tend to be "white" because they do not absorb photons with wavelengths in the visible range, they just scatter them. The color depends between the difference in energy between the highest occupied molecular orbital ("HOMO") and the lowest unoccupied molecular orbital ("LUMO"). The HOMO-LUMO gap for the average non-conjugated organic molecule tends to found in the UV range, which is invisible to most of us. In general, as you add more PI bonds into a conjugated system, the energy required for an electron to jump from the bonding
  4. How are you running your gel filtration? If there are no denaturing agents and the pH is right, it should look the same as native. In native, you are keeping the proteins in their native form. This means that the quaternary structure should remain conserved. On the SDS-PAGE you use denaturant (SDS to disrupt secondary/tertiary and a reducing agent such as beta-mercaptoethanol to reduce the disulfide bridges) to denature your protein. This will convert multimers into their monomeric form. When you run gel filtration you can choose your conditions to keep the protein native or you can a
  5. The sad truth is that we currently lack the methodology to study consciousness at that level in a truly scientific manner. It is debatable whether we will ever come up with a way to do so - finger crossed!
  6. The pKa for the imidazole conjugate acid is of around 7. You do not want your pH to go any lower than that, as the imidazole will become protonated and won't bind to the resin (might still get some elution from protonating the his-tag, but it's not very efficient). At pH 9, the imidazole will not be protonated, so it will still elute your protein. However, your protein will remain in the elution buffer, and for many proteins a pH of 9 is not optimal. I would add HCl until the pH goes down to 7.5. Add a bit, mix, measure pH. Repeat until you get to 7.5.
  7. In general, it would not be necessary to "cancel out some existing genes", unless the specific phenotype requires it. Yes, it is possible. Simple in theory, but very, very, very complicated in practice. For example, hair thickness, color, and straightness could be modified by inserting the appropriate gene variants. I don't think the hairline location could be manipulated genetically in an adult because that involves the expression of genes during the development rather than genes being currently expressed. I mean, you could do it, but that is not simple in theory at all. You'd have
  8. Is your protein a tetramer? If the monomeric unit is 36.5kD that could explain the results.
  9. From: All-D amino acid-containing channel-forming antibiotic peptides "The resistance of L- and D-cecropin A to enzymatic cleavage by the enzymes trypsin and InA (15) is illustrated in Fig. 3 Upper and Lower, respectively. The all-L peptide was hydrolyzed and inactivated rapidly by trypsin (50% in 20 min at a peptide-to-enzyme weight ratio of 2500: 1) or by InA (50%o in 20 min at a ratio of 200:1). In sharp contrast, the all-D peptide was completely stable to both enzymes, up to a concentration of trypsin 2000 times higher than needed for 50%o inactivation of the L peptide. In
  10. Is there a known genetic mechanism through which a given polypeptide can have its amino acid sequence inverted? For example: A DNA sequence is translated into the sequence: N-MKTSTRFLDGYFPVAANK-C -Mutation occurs- Which leads to the production of: N-MKNAAVPFYGDLFRTSTKM-C The obvious problem is that an inversion will invert the codon sequences (ex. CUU GGA-> AGG UUC = LG-> RU). Is there any known mechanism in nature through it is possible to change something like "AAU UCU GAC" into "GAC UCU AAU"? Furthermore, I've been running blast searches using inverted amino acid sequences
  11. Interesting, do you know of any books/papers where I can read more about this? I haven't been able to find anything on endorphin release when popping joints. ~Thanks!
  12. Are you sure you added methanol? Try evaporating a pure methanol solution and see what happens.
  13. That would be a positively charged methyl carbocation. CH3+
  14. Are you sure it's not spelled "Raffinose"?
  15. Hello! I have been trying to find a ribozyme which can cleave peptide bonds but have had no luck. Do any of you know whether one of these has been artificially produced? Is there any reason why it would be impossible to make one? I would like to make some proteases capable of breaking a specific peptide bond, and I was thinking that it could perhaps be easier to evolve one from RNA than from a protein, but I am not familiar enough with the field to know whether this is viable or not.
  16. I think you may be misunderstanding the term. In this context, "acquired trait" refers to a trait that is acquired during the organism's lifetime. So for example; if my muscle mass increases because I do a lot of exercise or I eat a lot of food and become really fat, these would be acquired traits or acquired characteristics. This is because these changes in the phenotype do not come because of changes in the genotype, but because of the interaction genotype's interaction with the environment. A novel trait that emerges due to a mutation is not an acquired trait. You can see a simple e
  17. Thank you Michel, that's a very interesting paper.
  18. On several ocations I've stumbled upon explanations like "Photosystems in plant ancestors evolved in a different environment and now it's sort of "stuck" the way it is, it's too hard to change it", "The plant would become too hot!", and "The plants can't handle so much energy". I am a bit skeptical about these explanations, but if you have any data testing any of these hypothesis I'd love to know about it. While reading "Photobiology: The Science of Life and Light" (Amazing book) I stumbled upon what looks like an explanation. The problem is that I can't fully understand it, and I would li
  19. I don't think the results are contradictory. The second study did challenge the assumption that multiple-choice decisions are evenly shared among the decision-makers in the colony, but this doesn't really affect the outcome of the first study. The first paper "Rationality in collective decision-making by ant colonies" by Pratt et al. focused on one of the principles of rationality that is commonly violated by several animals, including humans. A = B are perceived as equal. However, when C is added and it is dominated by one of them but not both, the one which dominates C is now preferred
  20. Don't expose the queen to the mutagen, expose the eggs. A strong mutagen will just end up killing all of your ants. You could expose them to UV light, which will increase the mutation rate by a smaller amount, but you will probably end up killing the ants as well to be honest. As far as I am aware, evolutionary biologists who perform selection experiments on arthropods do not use mutagens. You really don't need them, you just need an organism which is easy to maintain in the lab and has a high reproduction rate, like Drosophila sp. and Gryllus sp. because variation and mutations are
  21. I think this is quite interesting, so I've decided to do some reading. I have personally induced tonic immobility on several creatures. The most common way to achieve this on vertebrates is to turn them upside down, and I do this to frogs very often. In that video, the technique they are using is called the "Pinch Induced Behavioral Inhibition" (PIBI) or "Clipnosis", which was described by some veterinarian researchers from Ohio State University in 2008. The paper is titled "Pinch-induced behavioral inhibition
  22. Apparently some Ambystomatids are trying to keep up with the Elysia! http://www.nature.com/news/2010/100730/full/news.2010.384.html They probably still need a few millennium to figure out the gene transfer though, that is, if we don't kill them off before that.
  23. This sounds like fun! Do you know what "Invisible theater" is? It's when people act in front of an "audience" (Which can be, the people at the mall) without letting them know that it's all an act. The actors usually try to make the audience participate in the play without them knowing, and the audience should learn a lesson from this. I think that your project could also be considered a kind of "invisible theater" as you will be performing without the audience knowing, and they will interact in an indirect way with you through their expressions (And if you are lucky, perhaps someone will star
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