Protein synthesis

  • DNA (Deoxyribonucleic Acid)

    • Structure

    • Double helix (twisted ladder)

    • Backbone (sides) = sugar (deoxyribose) + phosphate

    • Rungs (middle) = base pairs

    • Nucleotide (building block)

    • Each nucleotide =

      • Phosphate

      • Sugar (deoxyribose)

      • Nitrogen base

    • Bases

    • A (Adenine)

    • T (Thymine)

    • C (Cytosine)

    • G (Guanine)

    • Base Pairing

    • A ↔ T

    • C ↔ G

    • Function

    • Stores genetic instructions

    • Organized into genes

    • Codes for proteins

  • RNA (Ribonucleic Acid)

    • Structure

    • Single-stranded

    • Sugar = ribose

    • Bases

    • A, U, C, G (U replaces T)

    • Base Pairing (DNA → RNA)

    • A → U

    • T → A

    • C → G

    • G → C

  • 3 Types of RNA

    • mRNA (Messenger)

    • Carries instructions from DNA

    • Contains codons (3 bases)

    • tRNA (Transfer)

    • Brings amino acids

    • Has anticodon (matches codon)

    • rRNA (Ribosomal)

    • Makes up ribosome

    • Helps build protein

  • Protein Synthesis

    1. Transcription (DNA → mRNA)

    • Happens in nucleus

    • DNA is copied into mRNA

    1. Translation (mRNA → Protein)

    • Happens at ribosome

    • mRNA read in codons (3 bases)

    • tRNA brings amino acids

    • Amino acids link → protein

  • Key Terms

    • Codon = 3 mRNA bases → 1 amino acid

    • Anticodon = tRNA match

    • Gene = DNA segment coding for protein

    • Protein = chain of amino acids

  • The Whole Flow (MEMORIZE THIS)

    • DNA → mRNA → Ribosome → tRNA → Amino Acids → Protein

  • Memory Hacks

    • DNA = blueprint

    • mRNA = message

    • tRNA = transporter

    • rRNA = builder

    • A-T, C-G (DNA)

    • A-U, C-G (RNA)