AP Biology / Unit 1: Chemistry of Life
1.6 Nucleic Acids
Notes
- DNA: deoxyribose, bases A, T, C, G, double-stranded helix.
- RNA: ribose, bases A, U, C, G, usually single-stranded.
- Strands are antiparallel; bases pair A–T (A–U in RNA) and C–G by hydrogen bonds.
Practice
Which base is found in RNA but not DNA?
U replaces T.
A DNA strand is 5′-ATGC-3′. Its complement is:
Complementary and antiparallel.
The two DNA strands are held together by:
Base pairs hydrogen bond.
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