Study guides › B/B › Biochemistry
Nucleic Acid Biochemistry
DNA and RNA are polymers of nucleotides. You will draw the building blocks, explain base pairing and helix forms, interpret melting curves and hybridization, compare RNA types, and understand the chemistry behind PCR and Sanger sequencing.
Study this chapter in PrepMed (free)
What this chapter covers
- Nucleotides & Nucleosides. Every nucleic acid question starts with the parts list: base, sugar, phosphate, and how they connect.
- DNA Structure & Base Pairing. The double helix, Chargaff's rules, and A/B/Z forms are all fair game for passages and one-liners.
- Denaturation, Melting & Hybridization. Melting curves and hybridization conditions turn base-pairing rules into measurable numbers.
- RNA Types & Functions. Know the main RNA classes, their sizes, and one signature feature of each.
- PCR & Sequencing Chemistry. PCR and Sanger sequencing apply base pairing and DNA polymerase chemistry directly, so you can reason through them.
Key points to know
- Nucleoside lacks phosphate; nucleotide has it
- Purines: A, G (two rings). Pyrimidines: C, T, U (one ring)
- Strands are antiparallel; B-DNA is right-handed, 10.5 bp per turn
- A=T (2 H-bonds), G≡C (3 H-bonds)
- Melting breaks H-bonds and stacking, not phosphodiester bonds
- Hyperchromic effect: A₂₆₀ rises as DNA melts
- RNA: ribose, uracil, usually single-stranded
- rRNA is the most abundant RNA; tRNA is the smallest of the three core types
Try a practice question
Which of these is a pyrimidine base?
- Adenine
- Thymine
- Guanine
- Ribose
Show the answer
B. Thymine has a single six-membered ring. Adenine and guanine are purines with fused rings, and ribose is a sugar, not a base.
Common questions
What does this chapter cover?
Nucleic Acid Biochemistry covers Nucleotides & Nucleosides, DNA Structure & Base Pairing, Denaturation, Melting & Hybridization, RNA Types & Functions, PCR & Sequencing Chemistry.
What should I know first?
Nucleoside lacks phosphate; nucleotide has it Purines: A, G (two rings). Pyrimidines: C, T, U (one ring) Strands are antiparallel; B-DNA is right-handed, 10.5 bp per turn
24 original practice questions accompany this chapter in the app. Spaced review brings missed ideas back at the right time; it helps memory but cannot promise you will not miss an idea again.