According to scientists, the human genome consists of protein-coding and non-coding regions; according to scientists, DNA comprises of 1 percent protein-coding genes and 99 percent noncoding genes (Zhang & Lupski, 2015).
Noncoding DNA does not take part in protein synthesis. With research, it became evident that some part of it is essential for cell functioning, most distinctively regulating gene activity.

For instance, noncoding DNA consists of particular sequences that perform the function of regulatory elements, which dictate the on and off function of genes. These regions provide sites for attachment of specialized proteins, such as transcription factors, and regulate the process by which information from genes is converted into proteins (Thomas & Kejariwal, 2004).

Multiple types of regulatory elements are present in noncoding DNA, such as Promoters, which are just in front of the gene and provide binding sites for proteins that help in the process of transcription. Enhancers are another type of regulatory element that has binding sites for proteins that assist in inactivating transcription. Proteins that repress transcription have their binding sites located on silencers.

Proteins that control transcription in multiple ways are present on insulators. Some insulators prevent transcription by blocking enhancers. Others repress gene activity by preventing structural changes in the DNA. Moreover, both functions can also be complete by some insulators.

Protein Synthesis

Noncoding DNA has certain regions that play a role in the synthesis of multiple types of RNA molecules. Specialized RNA molecules which result from noncoding DNA include ribosomal RNAs and transfer RNAs, which participate in the assembling of amino acids, the building blocks of proteins.

Short lengths of RNA called microRNAs halt protein synthesis, and long noncoding RNAs are longer lengths of RNA that play multiple roles in modulating gene activity. Noncoding DNA also contains some structural elements of chromosomes. For example, telomeres are  a result of contionous noncoding DNA sequences at the ends of chromosomes.

While genetic material is in the copying process, telomeres protect the ends of chromosomes from degradation. Satellite DNA results from repetitive sequencing of noncoding DNA, which is a part of other structural elements. The X-shaped chromosome pair has a constriction called the centromere, which satellite DNA forms. Heterochromatin, which is condensed DNA, is crucial for maintaining the chromosome integrity and regulating gene activity, is also formed by satellite DNA (Gloss & Dinger, 2018).

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