Lecture Notes: Anabolic Reactions and Protein Synthesis

Overview

• Catabolic Reaction: Breakdown of glucose, usually with oxygen, producing 30-32 ATP.
• ATP Use: Used to produce large biomolecules (e.g., DNA, RNA, proteins).

Anabolic Reactions

• Purpose: Build large biomolecules from smaller ones using ATP.
• Examples:
  • Nucleotide Synthesis: For DNA and RNA.
  • Protein Synthesis: Focus of this lecture.

Protein Synthesis

• Comprised of two main steps:
  • Transcription
  • Translation

Transcription

• Location: Nucleus
• Process:
  • DNA gene used as a template to create messenger RNA (mRNA).
  • mRNA is a polymer of nucleotides.
  • Differences from DNA:
    • Sugar in nucleotides: Ribose (RNA) vs. Deoxyribose (DNA).
    • Base Uracil (RNA) replaces Thymine (DNA).
• Function: mRNA is shorter than DNA, representing just enough nucleotides to specify a protein.
• Outcome: Produces mRNA which exits nucleus to cytoplasm, binds ribosomes.

Translation

• Location: Cytoplasm
• Process:
  • mRNA sequence read by ribosomes to assemble amino acids into proteins.
• Concept: Similar to translating languages.
  • From nucleic acids (nucleotides) to proteins (amino acids).

Key Concepts

• Transcription: Staying in the "language" of nucleic acids (DNA to RNA)
• Translation: Changing "languages" from nucleic acids to proteins (RNA to proteins)
• mRNA acts as an expendable copy that can be translated multiple times before degradation.