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Everything posted by Greippi

  1. When I started my biochemistry degree, a lot of people on the course didn't have a particularly good background/interest in chemistry, and I was told that my knowledge with chemistry would give me an advantage in certain things. However, I don't know about medical biochemistry, but on my course there was a lot of opportunity to select the areas you're best in after the first year in which you acquitre the chemistry basics - for example I went in to the area of molecular biology, whereas other people moved towards microbiology or genetics. What I'm trying to say is that if you have a genuine interest in the subject you should be fine, but you should be prepared to do quite a bit of chemistry - especially in your first year. Perhaps you could give me the course outline so I have an idea what you'll be doing - on the face of it they may look like they don't contain much chemistry - but due to the very nature of the subject there will be quite a bit! You never know though - you might find you become interested in chemistry once you start the course - before I started I hated physics, but now I love it. Have you thought about getting into contact with the university to see what they say?
  2. Personally I would first broadly sort them in to gram negative and gram positive.
  3. This is very interesting. One of the main developing fields in photosynthesis research is mapping out how the photosynthetic machinery arrange themselves on the photosynthetic membrane (using techniques such as AFM; couple of references below if anyone's interested). The arrangement has implications for the high efficiency of the system even if a component is knocked out. This quantum idea makes the picture fall in to place a lot more - exciting stuff! Sener MK, Olsen JD, Hunter CN, and Schulten K (2007) Atomic level structural and functional model of a bacterial photosynthetic membrane vesicle . PNAS USA 104, 15723-15728 Dror Noy (2008) Natural photosystems from an engineer’s perspective: length, time, and energy scales of charge and energy transfer. Photosynthesis Research 95:23–35 And here's the reference to the original Nature paper the article was based on: Nature 463, 614-615
  4. Also depends on what's in the flask and how tightly it's wedged in there. If it would be safe to do (i.e. if there was just a bit of water or nothing in there), and if the stopper isn't wedged in too tightly, might be an idea to gently heat the flask, thus slightly increasing gas pressure inside, and loosening the stopper a little so it might just fall out when you upend it.
  5. A simple google search will give you the answer you need (Hint:semi-quantitive will give an estimate, quantitative will give you an exact answer).
  6. That's how I would approach it myself, although I have never done such a thing. As for the cells surviving the procedure - unless I misunderstand what you want to do (which, in retrospect I think I do), when you're doing whatever you'll be doing to purify the protein, only use some of the cells, just leave other cells that are producing your proteins to grow untouched so you have some left over in reserve.
  7. True, they can be. They can be produced in response to bacteria and other microbes and microbial products. For example, double stranded RNA (found in some viruses), when encountered by a certain immune cell may trigger interferon production.
  8. CharonY pretty much covered it. I might be able to come up with another possibility if I knew what the enzyme was, and how you're measuring for activity.
  9. My view is that you shouldn't be able to own or patent a naturally occurring gene, as it's a discovery, not an invention. Which, on reading your post in more detail, has already been said!
  10. Edit button's disappeared so I'll say I did, of course, mean E. coli not E. coil there! Xenopus laevis is used as a model organism because it has a "very manipulable embryo" and is useful in developmental biology. It can also swallow its own head and skull by curving its lips around its head and sucking. But that hasn't been found to be useful to science yet.
  11. Absolutely anything you can think of that comes under the realm of biochemistry/genetics/molecular biology/microbiology. And the description of "fire breathing dragon" can be applied loosely - I got extra marks for my green fluorescent protein idea, because unlike many other ideas involving actual fire, it would actually be possible. It expects a critical analysis of your ideas too.
  12. Don't forget to include a historical perspective: e.g. the whole DNA thing with Rosalind Franklin.
  13. Often it just so happens that way. For example, there's nothing special about E. coil, sure it has many useful qualities for being used as a model organism but it's pretty much chance as to why it's become the most studied bacterium.
  14. You have lymph nodes in your throat region. All blood/fluids drain in the lymph nodes and this is a primary site for cells of your immune system to encounter infection. This is why your throat gets swollen. The bacteria isn't necessarily JUST in your throat, but that's where you're seeing the signs of inflammation because that's where some lymph nodes are. Circulating the antibiotic around the body maximises the chance it'll catch all the bacteria. Orally administrated antibiotics reach a perfectly effective concentration for killing a bacterial infection. For more resistant/severe infection antibiotics can be administered directly into the blood stream.
  15. Well of course there are problems knowing whether you've got the right open reading frame, as well as knowing whether you're actually in a gene or not. But other than that, i have never had any problem (I only have limited experience though).
  16. They diffuse throughout the blood stream, and when they meet a target they bind to it. They don't neccessarily localise to the throat. Also, just because inflammation is seen only in the throat, it doesn't mean that the bacteria are only present there. Antibiotic resistance put simply: You have a population of bacteria, all with slightly different genes (normal variation within a population). They will all have slightly varying susceptibility to being killed by the antibiotics. The ones with high sensitivity to antibiotic will be killed off first. The ones with more resistance that survive longer have time to replicate, so you get more bacteria present with higher resistance. And so on... - don't forget that these bacteria can spread to other people too. eventually you get a pool of bacteria that are completely resistant to antibiotic.
  17. Well, as routine a hospital would do tests for heart attack. Elevated levels of troponin remain in the blood for 5-14 days after a heart attack. As well as an ECG, this should be the first port of call. Heart attacks are usually characterised by extreme pressure as well as pain in the chest, which often radiates to the neck and left arm. Although some people only get heart burn type pain.# EDIT: sorry, someone's already pretty much said this.
  18. Don't worry. I don't find it hard, so it depends on the person! And if you have problems, you can always post here for help!
  19. If anything, my biochemistry masters dissuaded me from medical research hah!
  20. The question is pretty insanely diverse, so you gotta pick a direction that interests you the most and you are most knowledgeable about. So to take one path, the way I would approach it: once antibody has bound to antigen - how does that help to eliminate infection? What goes on to bind antibody-antigen complex? You might want to look at all the cell types that possess Fc receptors. That's just one starting point. Of course, it would be best to cover as broad a selection as possible: do a mind map thingy to come up with more ideas. Once you've got a bit further I can help you a bit more if you need it.
  21. Awesome, you're from University of Sussex, love Brighton - I almost decided to go there for my degree!

  22. We can't digest the cellulose in grass on our own (but commensal organisms in our gut can, releasing some nutrients for us). However, by eating grass, it is likely that this will cause a stomach upset, causing you to lose vital nutrients and fluid and putting you in an even worse situation than you would have been if you hadn't eaten the grass. Of course there are some plants in the wilderness that will be edible so if you think you're going to get lost in the wilderness, it is worth looking these up!
  23. I believe in this case it means something like "this also means/can be written as". Not entirely sure though.
  24. The whole process of signalling (e.g. binding of a cytokine to a receptor and initiating a response in the cell) is very complex, so I'm going to give you some very broad simple answers that should help. I'm not entirely sure about this one with this specific example, but I would assume there are more than one. A cell can alter the number of receptors it expresses on its surface, the more receptors it has, the more receptive the cell will be to what the receptors bind. Since signalling pathways are very complex, there will have been another molecule along the line that determines how many receptors are expressed on the cell surface. For example, there are certain conditions under which a cell would want to be more receptive to a certain signal, than other times. Different receptors have different affinity for their ligands. For example, HYPOTHETICALLY, we have a cell that signal A increases the rate of protein synthesis, and signal B represses protein synthesis. Since signal A causes huge amounts of energy to be put in to synthesising proteins, it is more important that this signal pathway is tightly controlled. In this hypothetical case, it would be worse for the cell to expend unneccessary energy. Therefore, higher concentrations of signal A would be needed to produce an effect than signal B. It goes further than that though, once the ligand is bound the the receptor, it sets off a signal cascade within the cell which involves interactions between many other proteins. This introduces different control points to ensure the cell responds to the signal appropriately. SO, in your example, the cell would respond to whichever signal it deems "most important". HOWEVER, it is extremely unlikely that the cell would encounter opposite cytokines in sufficient quantities to initiate a response at the same time. The receptor protein makes many contacts with the ligand molecule. The more easily these contacts are made the higher the affinity. Also important are the times it takes for the ligand to stay bound to the receptor, the time it takes for the ligand to fall off the receptor, and how long it takes for another ligand molecule to bind. Sometimes receptors are desensitised, so that even if more ligand binds, they do not respond to the signal and activate the signalling pathway within the cell. There are other factors as well, but that's the simplest. I answered that a bit above. It's unlikely. Someone may be able to provide input as to if this does ever happen, but I would assume that would be in rare cases.
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