An enzyme called RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. Transcription begins at a region known as the promoter. This process is divided into 3 stages: initiation, elongation Elongation Polymerase Chain Reaction (PCR), and termination. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(a) tail. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. DNA Types and Structure is used as a template to make mRNA mRNA RNA sequences that serve as templates for protein synthesis. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. Transcription is the process by which DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Transcription of genetic information is the first step in gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Students: Educators’ Pro Tips for Tough Topics.Fundamentals of Nursing: Clinical Skills.It holds the DNA together, allows it to dissolve in water, and is used by the cell for specific functions. While not as famous as the A's, T's, C's, and G's, DNA would not exist without its sugar-phosphate backbone. The DNA binding proteins perform important functions like copying the DNA (replication), controlling when, where and how much a gene gets read (transcription regulation), and much more. These proteins often have positive areas that bind strongly to the negative charge of the phosphate groups. The sugar-phosphate backbone has a negative charge that allows DNA to easily dissolve in water and is also used by proteins that bind the DNA. For example, the base pairing is critical to the processes of transcription and translation. The pairing of the nitrogenous bases that are connected to the sugar-phosphate backbone play a key role in the ability of DNA to store and transfer genetic information. The structure of DNA is tied to its function. The sugar-phosphate backbone, as mentioned, is an important component of DNA's double helix structure. These bases pair in very specific ways: A always pairs with T and G with C. The rungs connecting the two sugar-phosphate strands are created by pairs of nitrogenous bases. This backbone consists of alternating phosphate and sugar groups, with the sugar molecule of one nucleotide linking to the phosphate group of the adjacent nucleotide.Ĭonnected to each sugar is a nitrogenous base. The 'sides' of the ladder (or strands of DNA) are known as the sugar-phosphate backbone. If you look at a DNA double helix, it resembles a twisted ladder. The sugar in DNA is called a deoxyribose because it doesn't have a hydroxyl group at the 2' position. The carbons in the pentagon are numbered from 1'-4', starting with the carbon found to the right of the oxygen and moving clockwise. Four carbons plus an oxygen are part of the five-sided ring. Each nucleotide consists of a phosphate group, a nitrogenous base-adenine (A), thymine (T), cytosine (C), or guanine (G)-and deoxyribose.ĭNA's sugar, deoxyribose, has five carbon atoms, which are connected to each other to form what looks like a ring. But when it comes to DNA, the sugar involved is called deoxyribose.ĭeoxyribose is one of the three components of nucleotides, the building blocks of DNA. When you hear the word sugar, you may think of the white table sugar which sweetens coffee or tea.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |