A portion of a DNA template strand has the base sequence 5′-...ACGCGATGCGTGATGTATAGAGCT...-3′

Which is the third amino acid added to the polypeptide chain?

Key Concepts

DNA Transcription

DNA transcription is the process by which a segment of DNA is copied into RNA by the enzyme RNA polymerase. During transcription, the DNA template strand is read in the 3' to 5' direction, and a complementary RNA strand is synthesized in the 5' to 3' direction. This process is crucial for converting genetic information stored in DNA into messenger RNA (mRNA), which carries the code for protein synthesis.

Codons and Amino Acids

Codons are sequences of three nucleotides in mRNA that correspond to specific amino acids during protein synthesis. Each codon is translated into an amino acid by the ribosome, which reads the mRNA sequence. The genetic code is universal, meaning that the same codons specify the same amino acids across different organisms, allowing for the translation of mRNA into a polypeptide chain.

Translation Process

Translation is the process by which ribosomes synthesize proteins using the mRNA transcript produced during transcription. It involves the decoding of mRNA codons into a sequence of amino acids, forming a polypeptide chain. The ribosome facilitates the binding of transfer RNA (tRNA) molecules, each carrying a specific amino acid, to the corresponding codons on the mRNA, ultimately determining the order of amino acids in the resulting protein.