During gene expression DNA is being transcribed RNA, the non-coding sections are removed. The remaining coding segments are connected. This process is called
Huh
The answer is splicing.
Splicing is right
The process you are referring to is called splicing. Splicing occurs during the maturation of RNA molecules in eukaryotic organisms.
To understand how splicing works, let's first examine the structure of a typical gene. Genes consist of both coding regions, known as exons, and non-coding regions, known as introns. During transcription, the DNA sequence of a gene is copied into a precursor messenger RNA molecule (pre-mRNA). This pre-mRNA molecule contains both exons and introns.
The splicing process involves the removal of the introns from the pre-mRNA molecule and the joining together of the exons to form a mature messenger RNA (mRNA) molecule that can be used to produce proteins.
To perform splicing, a complex called the spliceosome is involved. The spliceosome consists of small nuclear ribonucleoproteins (snRNPs) and other associated proteins. These snRNPs recognize specific sequences at the boundaries between exons and introns, known as splice sites.
The splicing process can be broken down into two main steps:
1. Recognition and cleavage: The spliceosome recognizes the 5' splice site at the beginning of the intron, as well as the 3' splice site at the end of the intron. It also identifies a specific sequence within the intron called the branch point, located close to the 3' splice site. The spliceosome then cleaves the pre-mRNA at the 5' splice site, releasing the intron as a separate molecule called the lariat structure.
2. Exon ligation: The spliceosome brings together the 3' end of the upstream exon (located before the intron) and the 5' end of the downstream exon (located after the intron). These ends are connected, and the intron is released as a lariat structure. The resulting spliced mRNA molecule contains only the coding exons, which can now be translated into proteins.
Splicing is crucial for generating the diversity and complexity of proteins produced by eukaryotic organisms. Alternative splicing allows different combinations of exons to be joined together, resulting in the production of multiple mRNA variants from a single gene. This process significantly expands the proteome and contributes to the functional versatility of cells and organisms.
In summary, splicing is the process by which introns are removed from pre-mRNA molecules, and exons are joined together to form a mature mRNA molecule during gene expression. The splicing process is mediated by the spliceosome and involves recognition and cleavage of splice sites, followed by the ligation of exons.