Figure 5From: Primordial soup or vinaigrette: did the RNA world evolve at acidic pH?A possible scheme for non-enzymatic RNA replication at pH 4-5. (a) tRNAGly(GCC) forms dimers through its GCC anticodon due to hemi-protonation of the central cytosine at pH 4-5 [37](b) At pH 4-5, C-rich (GCC) n sequences might produce C-rich duplicates by non-enzymatic replication. Base pairs involving hemi-protonated cytosines are indicated by (+).Back to article page