Molecular Basis of Inheritance Cheat Sheet

Key Definitions

• DNA (Deoxyribonucleic Acid): Molecule that carries genetic information. ✅

• RNA (Ribonucleic Acid): Molecule involved in protein synthesis. ✅

• Gene: Segment of DNA that codes for a protein. ✅

• Chromosome: Structure made of DNA and proteins; carries genes. ✅

Important Concepts

DNA Structure

• Double Helix: Two strands of nucleotides wound around each other. ✅

• Nucleotides: Composed of a sugar, phosphate group, and nitrogenous base (A, T, C, G). ✅

Replication

• Semi-conservative: Each new DNA molecule contains one old strand and one new strand. ✅

• Enzymes:

• Helicase: Unwinds DNA. ✅

• DNA Polymerase: Synthesizes new DNA strands. ✅

Transcription & Translation

• Transcription: Synthesis of RNA from DNA. ✅

• Translation: Synthesis of proteins from mRNA. ✅

Key Formulas

• A + T = C + G (Chargaff's Rule) ✅

• mRNA = template strand of DNA ✅

Common Mistakes to Avoid

Common Mistake: Confusing DNA replication with transcription. Remember, replication copies DNA, while transcription converts DNA to RNA.

Memory Tricks

Tip: "A T C G" — "Apples in Trees, Cars in Garages" for remembering base pairing (A-T, C-G).

Key Diagrams

  A  T
  |  |
  G  C

   DNA Replication
   ----------------
   Helicase ---> Unwinds
   DNA Poly ---> Synthesizes