Texas A&M University (TAMU) BIOL111 Introductory Biology I Exam 3 Practice Exam

Gene expression involves the processes of transcription and translation, which are essential for converting genetic information from DNA into functional proteins.

During transcription, the DNA sequence of a gene is copied into messenger RNA (mRNA). This step involves the enzyme RNA polymerase, which unwinds the DNA and synthesizes a complementary RNA strand based on the DNA template. The resulting mRNA strand carries the genetic code needed for the next stage of gene expression.

Once transcription is complete, processing of the mRNA may occur, which includes capping, polyadenylation, and splicing to create a mature mRNA that is ready for translation. After processing, the mRNA is transported out of the nucleus and into the cytoplasm.

Translation is the next stage, where the mRNA sequence is read by ribosomes, and transfer RNA (tRNA) molecules bring the appropriate amino acids in accordance with the mRNA codons. This process builds a polypeptide chain, eventually folding into a functional protein.

This combination of transcription and translation is fundamental to gene expression, as it transforms the genetic code stored in DNA into a functional product that plays a role in the organism's traits and functions.