the functions of nucleic acids

the functions of nucleic acids

1. storage

   • double helix
     • prokaryotes
       • liner DNA that exists as chromosomes
       • long DNA
       • wrapped around histones
       • triplets / codons
     • eukaryotes
       • circular chromosome
       • short DNA
       • supercoiled to fit in cell

2. ribonucleic acid

   • protein synthesis
     • 1st stage, transcription
       • mRNA
         • a complementary copy of DNA strand
         • carries the genetic code from DNA to the ribosomes to make a protein
         • made during transcription by RNA polymerase
       • eukaryotes copy introns and exons / pre mRNA
         • splicing then occurs in the nucleus producing mRNA
       • prokaryotes copy all DNA
     • 2nd stage, translation
       • tRNA
         • has an amino acid binding site on it
         • has an anticodon thats complementary to the first codon
         • it carries the amino acids used to produce the protein
         • in a clover shape
   • single stranded
   • phosphate group, pentose sugar and 4 base pairs
     • adenine (A), uracil (U), cytosine (C), guanine (G)
     • adenine (A), thymine (T), cytosine (C), guanine (G)
     • complementary base pairing, A and T, C and G

3. deoxyribonucleic acid

   • double stranded

4. amino acids

   • universal
     • the same triplets code for the same amino acids in all living organisms
   • degenerate
     • some amino acids are coded for by more than one base triplet
   • non overlapping
     • one triplet produces one amino acid
     • read in sequence