SDN members see fewer ads and full resolution images. Join our non-profit community!

bio questions

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

  1. arpitpatel86

    arpitpatel86 2+ Year Member

    May 9, 2008
    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 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?
  2. SDN Members don't see this ad. About the ads.
  3. userah

    userah 7+ Year Member

    Aug 9, 2007
    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

    arpitpatel86 2+ Year Member

    May 9, 2008
    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 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 Dentist 7+ Year Member

    Oct 25, 2006
    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

    smile101 2+ Year Member

    Dec 4, 2007
    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

    osimsDDS 5+ Year Member

    Jun 8, 2007
    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

    Dencology 2+ Year Member

    Mar 7, 2008
    what is the anticodon to this DNA strand?
  9. osimsDDS

    osimsDDS 5+ Year Member

    Jun 8, 2007
    how is that a DNA strand it has Uracil...thats an mRNA strand....

Share This Page