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Everything posted by BabcockHall

  1. I would not assume any particular value for Vmax. Instead I would rearrange the Michaelis-Menten equation into the form v/Vmax = (S)/{KM + (S)}. This means that the velocity one calculates will be relative to Vmax. I decided to avoid using concentration brackets in this comment, because I think that they might be causing the unwanted strikethroughs.
  2. I am familiar with some kinds of protein chromatography, but I now have to run a nickel column for the first time. The protein of interest bears a histidine tag, and uur protein is believed to be a dimer or possibly a tetramer of identical subunits. As is typical the nickel column is the first step after sonication of E. coli cells. How do I choose the best volume of gel to use? If I use too little, there will be loss of the protein in the load and wash. If I use too much, the protein is more dilute, and in some sense I am wasting gel. At first glance I can see that one issue is the need to estimate what fraction of soluble cell protein is the protein of interest. I might be tempted to estimate this as being no more than 20% of the soluble protein. A second issue is capacity of the gel, and based on my general knowledge of protein IEX chromatography it occurs to me that there might be some variation from one protein to another, based upon accessibility of the his tag.
  3. I am not sure what you mean by "absorbed topically via the sun."
  4. The short answer is that oxidation of food creates a proton motive force which is coupled to the synthesis of ATP from ADP and phosphate. It takes several chapters worth of lectures in biochemistry to provide a detailed explanation. I would be hesitant to bring heat directly into this discussion.
  5. I assume that you are referring to Serum glutamic pyruvic transaminase, also known as alanine aminotransferase. We cannot provide medical advice on this forum; that is best done by consulting your physician. You may find this link helpful in terms of background reading. https://www.summitmedicalgroup.com/library/adult_health/tst_sgpt_tst/
  6. Protein is an absolutely essential part of our diet. Without it, we would go into negative nitrogen balance.
  7. A good place to start might be to count carbon atoms and see whether any have been lost or added upon conversion to the products.
  8. https://www.statnews.com/2020/04/29/gilead-says-critical-study-of-covid-19-drug-shows-patients-are-responding-to-treatment/ Patients taking remdesivir recovered more quickly than those taking a placebo. Business Insider and CNN have stories.
  9. Muscle cells undergoing anaerobic consumption of glycogen produce more pyruvate than they can consume aerobically via the TCA cycle. The pyruvate is instead converted into pyruvate. Your second sentence implies that there is an additional way to make lactate, but there isn't.
  10. Are enzymes equally active at all pH values, or do they have an optimum pH? Does the balanced reaction produce/consume protons? The mechanism that you drew implies the answer. In other words if one used unbuffered water, would the pH of the water gradually change with time. With respect to why convert pyruvate into lactate, there are several ways to think about it. If a muscle cell did not, what would happen to the ratio of NAD to NADH within that cell?
  11. You might also ask which would pass through the plastic and which would not.
  12. John, If you are correct, then whoever made the drawing must have been smoking something.
  13. If you are looking for a basic reference book, you might find Fundamental Concepts of Bioinformatics by Krane and Raymer to be helpful, in that one of the authors is a biologist and the other a computer scientist. It is a bit out of date, but it is inexpensive.
  14. Something to bear in mind is that formal charges and oxidation numbers are both tools to help us keep track of electrons and charges. They make different assumptions about which atom owns the electrons.
  15. Please give us your thoughts first, and perhaps we can help. I would start by ruling out some choices.
  16. This topic really belongs in homework help. In that section, you may expect help but not answers. My hint is that you first make sure you have a solid grasp of ionic bonds and intermolecular forces.
  17. It might take me or someone else some time to find it, but I seem to recall reading somewhere that the connection between runner's high and endorphins has never been established.
  18. We are zooming, too. I am trying to learn how to use a Wacom Intuos, but it's the old dog/new tricks problem.
  19. HCl is soluble in many solvents. I used to buy a solution of at least 1 M in dioxane IIRC.
  20. It would not be a true solution; it would be heterogeneous. It could be that the problem is imperfect, as opposed to being a trick question. As someone who has written my fair share of homework problems, I can say that it easy to overlook difficulties like this. Nevertheless, the amount of HCl needed to neutralize it is still something that could be calculated.
  21. The calcium hydroxide should come into solution as one adds more HCl. I doubt that it is a trick question.
  22. You wrote, "An optical density of samples with different protein content constituted from 0.0237 to 0.0933." Is this correct? One problem that I see is that if your unknown has a larger absorbance than 0.0933, you will be doing an extrapolation, not an interpolation. I generally filter the Bradford solution the same day as I use it. When I want the highest accuracy, I prepare a standard graph on the same day as the unknown.
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