Gene Expression and Central Dogma

Gene Expression

Overview

• Gene expression is the process by which the information encoded in a gene's DNA is converted into a functional product, such as a protein.
• It involves the transcription of DNA into RNA and the translation of RNA into protein.

Central Dogma

• The central dogma is the sequence of events that describes how genetic information flows from DNA to proteins:
  1. Replication: DNA is replicated to produce an identical copy of the genetic material.
  2. Transcription: DNA is transcribed into RNA, which is a complementary copy of the genetic code.
  3. Translation: RNA is translated into protein, which is the final product of gene expression.

Transcription

• Initiation: RNA polymerase binds to the promoter region of the gene, marking the start of transcription.
• Elongation: RNA polymerase reads the template DNA strand and adds nucleotides to the growing RNA chain.
• Termination: Transcription is halted when the RNA polymerase reaches the terminator region.

Translation

• Initiation: The small subunit of the ribosome binds to the messenger RNA (mRNA) and reads the start codon.
• Elongation: Amino acids are brought to the ribosome by transfer RNA (tRNA) and added to the growing protein chain.
• Termination: Translation is halted when the ribosome reaches a stop codon.

Regulation of Gene Expression

• Transcriptional regulation: Gene expression is regulated at the transcriptional level through the binding of transcription factors to specific DNA sequences.
• Post-transcriptional regulation: Gene expression is regulated at the post-transcriptional level through the degradation or stabilization of mRNA.

Key Players

• RNA polymerase: The enzyme responsible for transcribing DNA into RNA.
• Ribosome: The complex responsible for translating RNA into protein.
• Transcription factors: Proteins that bind to specific DNA sequences to regulate gene expression.

Gene Expression

• Gene expression is the process by which DNA information is converted into a functional product, such as a protein, through transcription and translation.

Central Dogma

• The central dogma outlines the flow of genetic information from DNA to proteins through replication, transcription, and translation.

Transcription

• Initiation: RNA polymerase binds to the promoter region, marking the start of transcription.
• Elongation: RNA polymerase reads the template DNA strand and adds nucleotides to the growing RNA chain.
• Termination: Transcription halts when the RNA polymerase reaches the terminator region.

Translation

• Initiation: The small subunit of the ribosome binds to messenger RNA (mRNA) and reads the start codon.
• Elongation: Amino acids are brought to the ribosome by transfer RNA (tRNA) and added to the growing protein chain.
• Termination: Translation halts when the ribosome reaches a stop codon.

Regulation of Gene Expression

• Transcriptional regulation: Gene expression is regulated through transcription factor binding to specific DNA sequences.
• Post-transcriptional regulation: Gene expression is regulated through mRNA degradation or stabilization.

Key Players

• RNA polymerase: The enzyme responsible for transcribing DNA into RNA.
• Ribosome: The complex responsible for translating RNA into protein.
• Transcription factors: Proteins that bind to specific DNA sequences to regulate gene expression.