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a bunch of biology questions

Discussion in 'DAT Discussions' started by joonkimdds, Dec 19, 2008.

  1. joonkimdds

    joonkimdds Senior Member
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    Hi, I got some questions :)
    Many of these are from DAT destroyer.

    1. t,m,r RNA are produced in transcription.
    I know that we make mRNA in transcription but I don't remember making t and r RNA.


    2. Many books are saying gluconeogenesis is not reverse of glycolysis. I agree because 3 steps are different out of 10 steps but it still doesn't change the fact that we start from pyruvate and end at glucose. But when I find the definition for gluconeogenesis, it says making glucose from non carbohydrate precursors. Does that mean pyruvate and all products until it reaches glucose are non carbohydrate?

    3. My class note says nicotinic receptor is always excitotary whereas adrenergic receptor can be excitatory or inhibitatory. According to DAT destroyer, it says acetylcholine has excitatory and inhibitatory which I think is wrong because my class note mentions it 3 times that it's ALWAYS excitatory.

    I need help to clarify these things.
    Thanks.
     
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  2. Panther85

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    1) rRNA and tRNA are part of the genome; therefore they come from the nucleus. make sure to look over the nucleolus and ribosomal production and the incorperation of rRNA into the ribosome.

    2) if it is (CH2O)n where n>1 then its a sugar

    3) According to DAT destroyer, it says acetylcholine has excitatory and inhibitatory--- YES ITS TRUE!!
    ach can act excitatorily on the postganglionic neuron of autonomic neurons. also it can act inhibitory on the effector like the heart
     
  3. gentile1225

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    i got this info from cliffs ap bio....

    trna is a short rna molecule that is used for transporting amino acids to their proper place on the mrna template.

    rrna are molecules that are the building blocks of ribosomes and the two subunits of the ribosomes coordinate the activites of the mrna and during during translation. they have 3 binding sites, one for mrna, one for trna, and one for a second trna.

    hope this helps.

    panther got to the other ones too fast for me but they sound good enough.
     
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  4. yankees27th

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    For your first question, all three are transcribed from the genome (where else would RNA come from anyway?). From there though, mRNA is spliced, sometimes edited, capped, polyadenylated, and sent to the cytosol whereas rRNA is transcribed and then sent to the nucleolus where it is processed and proteins are added to it to form ribosomes which go to the cytosol. I'm not sure about where tRNA goes directly after being transcribed, but they end up in the cytosol...

    Your second question has always confused me too and I'm not sure about your third question.
     
  5. doc3232

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    1. rRNA is made in the nucleolus, mRNA of course the normal way from transcription. tRNA, I would guess somewhere from the nucleus (not the nucleolus)

    2. You can make pyruvate from an amino acid and that doesn't look like reverse of glycolysis. Different route.
    Also, to answer your question about the noncarbo thing. What is the definition of a carbo?

    3. I think acetylcholine is ALWAYS excitatory on muscles. But it can be used on other site receptors that are not muscles.

    Hope this helps joonkim
     
  6. Panther85

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    2. anything that has (CH2O)n

    3. ACh is always excitatory on skeletal muscles bc it is part of the somatic nervous system. ACh acts inhibitory on cardiac muscle and slows the intrinsic heart rate down.
     
  7. doc3232

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    Cardiac muscle is a muscle???? Impossible.

    Well, there you go joonkim, ach inhibits cardiac
     
  8. joonkimdds

    joonkimdds Senior Member
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    Thank you all~ :D
     
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