🧬

Understanding the Protein Synthesis Process

May 12, 2025

Protein Synthesis Lecture Notes

Introduction

  • DNA results in traits, such as eye color, through protein synthesis.
  • Genes in DNA code for proteins that help create pigments, impacting traits like eye color.
  • Proteins are essential for various functions: transport, structure, enzymes, and protection.

Importance of Proteins

  • Proteins are crucial for life and have diverse roles.
  • Cells continuously synthesize proteins.

DNA and RNA Overview

  • DNA is mostly in the nucleus except for a few cases.
  • Some DNA is noncoding; some make inactive genes.
  • Genes coding for active proteins are crucial in this context.
  • RNA plays a key role in protein synthesis.

RNA and its Role

  • RNA is a nucleic acid with differences from DNA.
  • RNA's role is significant in the process of protein synthesis.

Protein Synthesis Process

Two Main Steps

  1. Transcription

    • Occurs in the nucleus.
    • DNA is transcribed into mRNA by RNA polymerase.
    • mRNA is a single-stranded RNA formed by complementary RNA bases.
    • mRNA undergoes editing before use.

  2. Translation

    • mRNA exits nucleus to cytoplasm and attaches to ribosome.
    • Ribosomes and rRNA are involved in protein building.
    • tRNA molecules in the cytoplasm carry amino acids (monomers of proteins).
    • tRNA reads mRNA codons in triplets, known as codons.
    • tRNA has anticodons that match mRNA codons, transferring specific amino acids.
    • Example: AUG codon on mRNA matches UAC anticodon on tRNA carrying methionine.

Codon Chart

  • Codon chart determines which amino acids correspond to mRNA codons.
  • AUG is a start codon; multiple codons can code for the same amino acid (e.g., leucine).
  • Example codon: CCA on mRNA codes for proline, with tRNA anticodon GGU.

Peptide Bond Formation

  • Amino acids are bonded by peptide bonds to form protein chains.
  • Process continues until a stop codon signals the end of protein synthesis.

Final Steps

  • Result of translation is a chain of amino acids directed by mRNA.
  • DNA was the ultimate director of protein synthesis.
  • Further protein folding and modification may occur.

Conclusion

  • Protein synthesis is a complex, essential process for life.
  • Continuous advancements and discoveries in molecular biology.
  • Encouragement for further exploration into the topic.

Full transcript