kapital Posted October 6, 2009 Share Posted October 6, 2009 When DNA is replicating, how can the polymerase add so many bases so fast? Where does she get them? 1 Link to comment Share on other sites More sharing options...
Mr Skeptic Posted October 7, 2009 Share Posted October 7, 2009 The bases are just floating around in solution, and occasionally collide with the polymerase. At the small scales, molecules move much faster than you might think. Link to comment Share on other sites More sharing options...
CharonY Posted October 7, 2009 Share Posted October 7, 2009 The nucleotides hang around. Not the pure bases. Also remember that the volume is rather low. Link to comment Share on other sites More sharing options...
Mr Skeptic Posted October 7, 2009 Share Posted October 7, 2009 (edited) Well, I could have called them deoxyribonucleotide triphosphates but didn't feel like it. Incidentally, two of the phosphates are removed to provide energy, just like ATP. Edit: As CharonY said, it's like but not the same as ATP, I forgot about the extra deoxy bit. Edited October 7, 2009 by Mr Skeptic oops Link to comment Share on other sites More sharing options...
CharonY Posted October 7, 2009 Share Posted October 7, 2009 (edited) Not quite, for DNA synthesis deoxy-ATP (and the respective other nucleotides) is used. Also ATP-dependent energy transfer is normally limited to a single phosphate residue (i.e. from ATP to ADP). Whereas during DNA polymerization PPi is removed. But yes, the principle is very similar. Edited October 7, 2009 by CharonY Link to comment Share on other sites More sharing options...
kapital Posted October 7, 2009 Author Share Posted October 7, 2009 Ok. Is the transport from cytoplasma to nucleus work of enyzmes? Is the transport of nucleotides to cell connected with the needs of cells? Link to comment Share on other sites More sharing options...
CharonY Posted October 7, 2009 Share Posted October 7, 2009 The nucleus possesses porins (essentially proteins that form a channel) that are large enough to let nucleotides pass. IIRC there was no difference in nucleotide concentration between between nucleus and cytoplasma, further indicating free diffusion. Link to comment Share on other sites More sharing options...
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