Molecular Basis of Inheritance: DNA Replication, Translation, Mutations

Understanding the Molecular Basis of Inheritance

Inheritance encompasses the passing of biological traits and characteristics from parents to offspring, shaped by the principles of genetics and molecular biology. Here we delve into the fundamental processes at play: DNA replication, translation, mutations, genetic code, and RNA transcription, which collectively contribute to our unique genetic makeup.

DNA Replication

Deoxyribonucleic Acid (DNA) serves as the blueprint of life. Because cells must divide and reproduce themselves, accurate duplication of DNA before division is essential. Double-stranded DNA unwinds, and new strands form complementary to the original templates—this process is known as semi-conservative replication (Figure 1).

Figure 1: Semi-Conservative DNA Replication.

Central Dogma of Molecular Biology

Francis Crick proposed the Central Dogma consisting of three main pathways: DNA to RNA, RNA to Protein, and Protein to Protein interactions. These pathways constitute the flow of genetic information within a cell.

Translation

From messenger RNA (mRNA) encoding specific amino acids comes protein synthesis, the formation of peptide chains (translation). Transfer RNA (tRNA) carries individual amino acids, decoding the mRNA template in conjunction with ribosomes.

Mutations

Changes in DNA sequences cause mutations, altering the encoded genetic information. Point mutations, frameshift mutations, and insertion/deletion mutations can lead to changes in phenotypes.

Genetic Code

Genetic code refers to the set of rules determining how the order of nucleotide bases in DNA corresponds to the amino acid sequence in proteins. Triplets of nucleotides define codons specifying amino acids for protein synthesis.

RNA Transcription

RNA transcripts are generated from DNA templates to form functional molecules. Messenger RNA specifies the amino acid sequence of proteins, while tRNA facilitates translating mRNA to protein.

Overall, understanding DNA replication, how genetic codes translate to proteins, and the role of mutations provides insight into hereditary traits, disease, and evolutionary processes.