Question

What do you mean by central dogma of Molecular Biology?

Hint:

The central dogma explains the essential process of how genetic information is converted into functional proteins. Remember, it's the flow from DNA to RNA to protein for most biological systems.

Answer 1

The central dogma of molecular biology is a fundamental concept that describes the flow of genetic information within a biological system. It was first proposed by Francis Crick in 1958 and outlines the process by which genetic information is transferred from DNA to RNA and finally to proteins. This process is crucial for cellular function and organism development. The central dogma can be summarized as follows: \[ \text{DNA} \xrightarrow{\text{Transcription}} \text{mRNA} \xrightarrow{\text{Translation}} \text{Protein} \] Explanation of the Process:
1. Transcription: The process begins with the transcription of DNA into messenger RNA (mRNA). In this step, a segment of DNA is copied into mRNA by the enzyme RNA polymerase. The mRNA serves as a blueprint that carries genetic information from the DNA in the nucleus to the cytoplasm, where proteins are synthesized.
2. Translation: In the cytoplasm, the mRNA is translated into a protein. Ribosomes read the sequence of the mRNA in sets of three nucleotides, called codons, which specify a particular amino acid. Transfer RNA (tRNA) molecules bring the appropriate amino acids, which are linked together to form a protein. The sequence of amino acids determines the structure and function of the protein.
3. Role of Proteins: Proteins are essential for carrying out various cellular functions, including catalyzing metabolic reactions (enzymes), providing structural support (cytoskeleton), and regulating cellular activities (hormones, antibodies). Proteins are the workhorses of the cell, executing the instructions encoded in the DNA.
Exceptions and Extensions:
While the central dogma primarily describes the flow of information from DNA to RNA to protein, there are some exceptions and extensions. For example, some viruses (like retroviruses) can reverse this flow, converting RNA into DNA via an enzyme called reverse transcriptase. This phenomenon is known as reverse transcription.