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Leroy

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Everything posted by Leroy

  1. Leroy

    Bacteria where???

    thanks a lot for the replies. just to paraphrase someone at that table "Isn't the inside of meat sterile?" and inside i was really cracking up. And these people call themselves scientists. I know that there is a difference between 'bad' bacteria and 'good' bacteria. And that those good ones are everywhere. I tried to reason with them that the stomach contains bacteria and your blood or your mouth but they all couldn't see that inside of a piece of meat they would also be present. thanks again for clearing that up
  2. I was recently discussing whether meat (bought in supermarket or at a butcher) has any bacteria inside of it. The whole idea started with the fact that some people prefer medium rare or bloody steaks and the argument that it was edible and not a threat to your health is that all possible bacteria are on the outside of the meat and not the inside. I tried reasoning with these people that through most of the meat we eat, blood runs through the animal when stil alive, thus there always being bacteria inside meat since blood always contains a certain amount of bacteria. Can anyone allaborate whether this is in fact true or was I the only mental patient at lunch that day??? Thanx
  3. No, with [(1,0,0,0),(3,4,0,0)] i mean the the space it spans. I hope this helps
  4. hi people, just started following a linear algebra course and i've run into some trouble trying to solve some problems in the book. I've been asked to calculate the projection of (1,2,3,4) unto [(1,0,0,0),(3,4,0,0)] Obviously they are not orthagonal as their in product is 3 and not 0. So you project the in sum of (3,4,0,0) and (1,0,0,0) = (3,0,0,0) (3,0,0,0) - (3,4,0,0) = (0,4,0,0) Now it is orthagonal, I project vector x on (1,0,0,0) = (1,0,0,0) Projection of vector x onto (0,4,0,0) I think is (0,1,0,0) This leads to V = (1,1,0,0) I was just wondering if anyone can do the calculations as well as I'm not able to confirm this. Thanx in advance
  5. I just read that it's possible for women to have 2 wombs. http://news.bbc.co.uk/1/hi/world/americas/3011241.stm And women with this condition (approx. 1 in every 55000 women) can also have 4 kidneys. It supposedly has something to do with the womb being formed in the 8th week of pregnancy, the same time the kidneys are formed. Although I have no clue what the connection between the two would be. Does anyone have more info on this??? correction: another site (i lost it) had the 55000 number. In the article which is linked at the top, says one in a 1000 women have this. It's even possible for these women to have to vagina's and two cervixes!!
  6. i had a look in my wonderful Biochemistry book (Stryer) and it has the biosynthetic route to heme. Glycine reacts with succinyl CoA which yields delta-aminolevulinate. The reaction is catalysed by delta-aminolevulinate synthase which is present in mytochondria. Two molecules delta-aminolevulinate condense to give the pyrrole porphobilinogen. The enzyme porphobilinogen deaminase catalyses the condensation of four porphobilinogens to form a linear tetrapyrrole. This then cyclises to uroporphrinogen III. A few other steps are required to change the degree of saturation of the ring and also a few side groups are changed to eventually form protoporphyrin IX. Iron is added to it to give heme. Actually more simple than I imagined. How plants do the same for chlorophyll is something I still have to look up if I have time.
  7. Leroy

    apples and pears

    well, i actually meant the shape of the fruit. And if its all to do with conserving energy, is the shape of an apple more conserving than that of a pear? I could imagine that it has something to do with the shape of the flower, but i wouldn't know for sure.
  8. Can anyone tell me how porphyrins like chlorophyll and haeme are synthesized in nature. Is there a difference for plants and mammals since plants don't have haeme (i think).
  9. i was always told that water above certain purity is actually not healthy for you as it hardly contains any ions, which your body need. You promote osmosis as all the salt in your body want to contaminate the pure water you just drank therefore depleting cells of essential salts.
  10. Leroy

    apples and pears

    Might be a weird question to any die hard biologist, but I was recently wondering why an apple grows the way an apple grows. I also thought of a different fruit similar to that of an appel (anatomically) and thought of a pear. And again my previous question arose in my little head as to why a pear grows the way a pear grows. Can anyone elaborate?? or any fruit for that matter
  11. Leroy

    Viagra

    sorry bout that... i read it the article through once and what i wrote here was off the top of my head and i see now that i made some mistakes.... not major ones.... btw, i was wondering what effect pyridine would have in this whole process. My idea was that it would coordinate with iron in guanylyl cyclase stronger than NO would. But then i could only see this as temporary ED than permanent.
  12. Leroy

    Viagra

    sadly i can't find any source claiming that it can in fact cause impotence, but i checked it with a collegue who had an article as to how viagra works. GTP is turned into cGMP when a NO molecule activates a phosphodiesterase (type 5) by binding to a haeme molecule attached to the diesterase. The cGMP makes for relaxation in the blood vessels and veins which allows blood to fill the penis. Pyridine should be able to bind even better to the haeme than NO and in doing so not allow for the phosphodiesterase to be activated, which in turn does not allow for cGMP to be made so no blood is released into the penis. Anyway, I hope this is a clear discription, but thanks to anyone who took the trouble to check it out.
  13. Leroy

    Viagra

    I was wondering how pyridine affects the body in such a way that it would cause impotence, as I work in a lab where it is used often. Would impotence by pyridine make the use of Viagra nulified, or would Viagra be able to stimulate the areas of the body which would otherwise be broken down by the pyridine.
  14. i think the whole cloning issue is so blown up by uber ethics people (whatever you would call them) it like saying inbreeding or cross-breeding is unethical yet most of us are a product of it. So it most of our food and drink. So i really think being against an idea simply because we don't know the long term effects is like saying you don't want to go to someone's house because you've never met them. Fear of the unknown plunged us into the dark age and people who did think most of us do these days were considered witches. I think the same kind of thing is happening now, in that the people who consider the possibilty of cloning are the witches of the 21st century.
  15. The time tree might be something we can't see directly (duh?) but i imagine it could be in higher dimensions or even 'outside' of our universe and as far as adapting is concerned, it would do this to avoid temperal paradoxes like you being in the future and past at the same time like meeting yourself in the past
  16. I'm no expert, but putting the words magical physical as to describe something doesn't seem very plausible... sorta oxymoron and the way i imagine time is that its like a tree. a central timeline is the trunk. this splits up into multiple roots which in turn split up as well. If one went back in time, you would basically go to a time and a new 'root' would 'grow'. The timeline you were in isn't accesable to you any more, but the people who don't time travel never notice the difference (except the time traveller wil be gone)
  17. i recently had a discussion with a friend of mine in which we were discussing the differences between men and women... or course not the obvious differences but the way their brains function differently. A question i had which neither of us could answer and neither could a couple of girls we asked is: If men are much more visually stimulated and react the way they do because of this visual stimulation, what do women have to compensate for it if one presumes that women aren't as visually stimulated as men. The thing i have problem with is the fact i believe that in recent years women have had the opportunity to become more visually stimulated and that is why proffesions which were first only accesable to men, are now becoming more popular to women. I don't think that women are any less visually stimulated than men, just in a different way. So, what do you people think?
  18. i started a new topic on the third of june in the biology section... anyone know where it went? thnx
  19. the nitrogen atom is a pretty strong nucleofile. And the carbonyl carbon is partially positive. the nitrogen can therefore attack the carbonyl carbon.
  20. k... thnx for the tips
  21. so is there a substance like cafeine which burns your glycogen but isn't diuretic?
  22. so if you drink some coffee at school, and you've got PE 15 minutes after you have drunken the coffee, does that mean the exercise you would do i actually bad for you? and btw, what do you mean by diuretic? When is a substance diuretic?
  23. I recently started working out and I remembered something from my biochemistry class. Cafeine activates a diesterase which turn cAMP into AMP making the body 'burn' it's glycogen. In order to get rid of fat better, would it be a good idea to drink some cafeine drink before you work out? And if so, how much cafeine would you need to consume and how long would it take before you could start working out? The thing is, i've got some love handles I want to take care of but if all i'm burning in the first 15 minutes of a workout is sugar couldn't I just burn that all away before starting my workout? BTW, is cafeine addictive in a physical way or a mental way? I wouldn't want get addicted to cafeine and endorphines at the same time...
  24. i don't know if this is a stupid question but i can't seem to figure out the solution to the problem presented. 'You measure the photosynthesis speed of a North European plant. You measure it both under normal circumstances and at high concentrations of oxygen. Below are the results. How is it that the net CO2 fixation is lower at a higher oxygen concentration? I figure that it's because photosynthesis already produces O2 and if there's a high concentration of O2 already present then the plants won't take up CO2.
  25. yeah thanx. i figured it out with the pdf before you posted the last post, but thanx for confirming my own ideas.
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