Nucleotides

Cards (20)

  • What are the functions of nucleotides?
    energy for metabolism(ATP) , enzyme cofactors (NAD+) , signal transduction (cAMP) , precursors of nucleic acids
  • What is a nucleobase?
    nitrogenous base
  • What is a nucleoside?
    nitrogenous base and pentose sugar
  • What is a nucleotide?

    Nitrogenous base + pentose sugar + phosphate
  • What is the pentose sugar in DNA and RNA?
    B-D-ribofuranose in RNA
    B-2-deoxy-D-riobofuranose in DNA
  • What is the characteristics of the phosphate group?
    Negatively charged at neutral ph , typically attached to 5' position (5'-triphosphates used to build nucleic acids) , nucleic acids contain one phosphate moiety per nucleotide
  • What are the characteristics of nucleobases?
    Derivatives of pyrimidine or purines , nitrogen containing heteroaromatic molecules , planar , absorb UV 250-270nm
  • What are the characteristics of pyrimidine bases?
    Cytosine is found in both DNA and RNA

    Thymine is found only in DNA

    Uracil is found only in RNA

    all are good H bond donors and acceptors , neutral molecules at ph 7
  • What are the characteristics of the purine bases?
    Adenine and guanine are found in both RNA and DNA
    good H bond donors and acceptors
    Neutral molecules at PH 7
  • What does Adenine look like?
  • What does guanine look like?
  • What does cytosine look like?
  • What does thymine look like?
  • What does uracil look like?
  • What are the characteristics of the B-N-glycosidic bond?

    In nucleotides the pentose ring is attached via this bond

    Formed: anomeric carbon of the sugar in B configuration

    formed to position N1 in pyrimidines and position N9 in purines

    This bond is quite stable toward hydrolysis, especially in pyrimidines

    Bond cleavage is catalyzed by acid
  • What is the UV absorption of nucleobases?
    250-270nm
  • What are the names / codes of the deoxyribonucleotides?
    da/damp (deoxydenylate)

    dG/dGMP (deoxyguanylate)

    dT/dTMP (deoxythymidylate)

    dC/dCMP (deoxycytidylate)
  • What are the codes/names of the ribonucleotides?
    A/AMP (adenylate)
    G/GMP (guanylate)
    U/UMP (uridylate)
    C/CMP (cytidylate)
  • What are the minor nucleosides in DNA?
    modification is done after DNA synthesis , 5-methylcytidine is common in eukaryotes , N6-methyladenosine is common in bacteria
    Epigenetic marker
  • What are minor nucleosides in RNA?
    Inosine: found in wobble position of the anticodon in tRNA

    Pseudouridine: found in trna and rrna , more common in eukaryotes