The Central Dogma

Central Dogma of Molecular Biology

• Central dogma describes the flow of genetic information: DNA → RNA → Protein.
• Involves critical biochemical substances: DNA, mRNA, tRNA, ribosomes, and proteins.

Location of DNA

• DNA is primarily located in the nucleus of eukaryotic cells.
• In prokaryotic cells, DNA resides in the cytoplasm, as they lack a defined nucleus.

Function of mRNA

• Messenger RNA (mRNA) serves as the intermediary between DNA and proteins.
• It carries genetic information from DNA to ribosomes, where protein synthesis occurs.

Proteins

• Proteins are large, complex molecules made up of amino acids.
• They perform a myriad of functions, including catalyzing reactions, providing structural support, and regulating cellular processes.

Determinants of Phenotypic Characteristics

• Phenotypic traits are determined by the expression of genes, influenced by both genetic and environmental factors.
• Genotype, the genetic makeup, dictates potential traits which are expressed as phenotype.

Transcription Enzyme

• RNA polymerase is the key enzyme responsible for transcription.
• It synthesizes mRNA from a DNA template during the transcription process.

Role of RNA Polymerase during Transcription

• RNA polymerase binds to a specific region of DNA, unwinding and separating the double helix.
• It catalyzes the polymerization of RNA nucleotides complementary to the DNA template strand.

Nitrogenous Base Interaction

• During transcription, Uracil (U) interacts with Adenine (A) in RNA.
• This substitution occurs as Uracil replaces Thymine (T) found in DNA.

Similarity of Transcription Process

• The process of transcription is most similar to DNA replication in terms of enzyme action and nucleotide pairing.
• Both involve complementary base pairing and enzymatic facilitation.

Function of RNA Polymerase During Transcription

• RNA polymerase assembles RNA nucleotides into a growing mRNA strand.
• It ensures accurate transcription based on the DNA sequence, allowing for correct protein production.