Protein Synthesis and Its Importance

Introduction

• DNA codes for genetic traits, like eye color.
• Eye color is determined by pigment, which is made possible through proteins coded by genes (portions of DNA).
• Protein Synthesis: The process by which DNA leads to protein creation.
  • Essential for life as proteins perform vital roles, such as:
    • Transport
    • Structural support
    • Enzymatic functions
    • Protection of the body

Role of DNA

• Most cells contain DNA located in the nucleus.
• DNA consists of genes that may or may not be activated.
• The discussion focuses on genes coding for active proteins.

Introduction to RNA

• RNA: A nucleic acid like DNA but with different properties.
• Plays a crucial role in protein synthesis.

Steps in Protein Synthesis

1. Transcription

   • Takes place in the nucleus.
   • Process:
     • RNA Polymerase enzyme connects complementary RNA bases to DNA.
     • Formation of single-stranded mRNA (messenger RNA).
     • mRNA editing is crucial post-transcription.
   • mRNA exits the nucleus to the cytoplasm.

2. Translation

   • Occurs in the cytoplasm at the ribosome.
   • Ribosomes consist of rRNA (ribosomal RNA).

Role of tRNA

• tRNA (transfer RNA) carries amino acids, the building blocks of proteins.
• tRNA identifies the amino acids to bring based on mRNA codons.
• Reads mRNA bases in triplets (codons, e.g., AUG).
• Anticodon matches the mRNA codon to specify the amino acid.

Codons and Anticodons

• Example: Codon AUG corresponds to the anticodon UAC on tRNA, carrying Methionine.
• Codon Chart: A tool to determine which amino acids correspond to specific mRNA codons.
  • AUG is a start codon, usually coding for Methionine.
  • Multiple codons can code for the same amino acid (e.g., Leucine).

Chain Formation

• Example: Codon CCA codes for Proline, tRNA with anticodon GGU carries Proline.
• Amino acids are linked by peptide bonds, forming a growing chain.
• Translation ends at a stop codon, signaling the end of protein building.

Outcome of Translation

• A chain of amino acids is formed based on mRNA coding.
• mRNA was complementary to DNA, hence DNA directs protein synthesis.
• Post-translation modifications (protein folding, transport).

Conclusion

• Protein synthesis is a complex, essential process involving DNA, mRNA, rRNA, and tRNA.
• Additional learning encouraged for deeper understanding (e.g., gene regulation, protein modification).

Stay curious and explore further topics related to protein synthesis and genetics!