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bio questions

Discussion in 'DAT Discussions' started by arpitpatel86, May 30, 2008.

  1. arpitpatel86

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    A DNA segment has the follwing sequence 5'CCGAAT 3' What would be the sequence of the transcribed m-RNA


    in an erythrocyte, where does the TCA cycle occur?
    a. Matrix of mitochondria
    b. Innermembrane of mitochondria
    c. cell membrane
    d. cytosol
    e. None of these
    Destroyer says that E is the correct answer. An RBC lacks mitochondra, there is no TCA cycle. The RBC derives its energy from glycolysis: anaerobic respiration occuring in the cytosol; the ETC is contained wthin the inner membrane of the mitochondria....

    I agree wtih the answer, but i dont agree with the ETC being contained within the inner mmebrane of the mitochondria...how could this be possible if RBC lacks mitochondria?

    #125 destroyer says norepinephrine is the primary neurotransmitter of the sympathetic nervous system.....but i thought it was epinephrine....i know both exist on symp.NS but isnt the ratio of epinephrine to norep 4:1 so wouldnt epinephrine be the primary neurtotransmitter?
     
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  3. userah

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    transcribed m-RNA segment will be 5' AUUCGG 3'

    a RBC doesn't do oxidative phosphorylation. It's got no mitochondria, thus no calvin cycle and no ETC. the ETC is contained within the inner membrane of the mitochondria. i don't see where you're getting confused about that...

    as for the norepi/epi. Not sure about that. They're both hormones and neurotransmitters but i think one is mainly involved with hormonal effects (epi) and the other is more involved with signaling between neurons (norepi). LIke i said, not sure. hopefully someone can confirm and refute and clarify.
     
  4. arpitpatel86

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    ok for the firs one ......why do u do it in reverse...bc sometimes u do it in the same direction and change the letters and sometimes u start from the opposite end?

    like dna--) mRNA
    sometimes if its like ATC on dna.....its TAG....and then it goes to AUC

    then sometims if its ATC.....it GAT....then its CUA...i dunno im sure all of this what i just did is worng but i get soo confused onthis questions pleaswe help
     
  5. Streetwolf

    Streetwolf Ultra Senior Member
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    The mRNA strand runs the other way, 3'-5' except you generally write it out in the 5'-3' direction. That's why he reversed it. Then the anticodon is the complement of THAT.
     
  6. smile101

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    mRNA is always transcribed from 5' to 3' direction, therefore you have to be careful when transcribing the given sequence. The 3' direction of dna is the 5' direction on rna. If you have any textbook with a pic of transcription, you should take a look at such details.

    The 4:1 ratio of epinephrine to norepinephrine is referring to its production in the adrenal medulla. Adrenal medulla is involved in sympathetic reponse by producing these catecholamines, but as a neurotransmitter, norepipnephrine is mainly used by the the sympathetic nerves themselves. Epinephrine has a hormonal function.
     
  7. osimsDDS

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    an erythrocyte will not use the ETC cycle because the final electron acceptor is Oxygen and since it carries oxygen it would use it to power the ETC cycle and therefore would be counterproductive. therefore it only uses anaerobic glycolysis to get energy...
     
  8. Dencology

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    what is the anticodon to this DNA strand?
    3'CCGUUA5'.
     
  9. osimsDDS

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    how is that a DNA strand it has Uracil...thats an mRNA strand....
     

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