o
p
o «\
05' P"C5'
H4W ä
C7( H7) 3 p4
\ / C5—C4
uc- W   T" \
l15 H6—C6     I N3H3
N1 — C2
04'       /x
\  ' 02
C4' ^cr
03'
C3'i
Hť
H2"
H
Uracil (U) RNA only
Thymine (T) DNAonly
O
H
Cytosine (C) both DNAand RNA
Adenine (A)
Guanine (G)