We've updated our Privacy Policy to make it clearer how we use your personal data. We use cookies to provide you with a better experience. You can read our Cookie Policy here. Deoxyribonucleic acid DNA and ribonucleic acid RNA are perhaps the most important molecules in cell biology, responsible for the storage and reading of genetic information that underpins all life.
They are both linear polymers, consisting of sugars, phosphates and bases, but there are some key differences which separate the two 1. These distinctions enable the two molecules to work together and fulfil their essential roles. Before we delve into the differences, we take a look at these two nucleic acids side-by-side. I Understand. Published: December 18, Last Updated: November 11, DNA encodes all genetic information, and is the blueprint from which all biological life is created.
At this point, at least in eukaryotes, the newly synthesized mRNA undergoes a process in which noncoding nucleotide sequences, called introns , are clipped out of the mRNA strand. This process "tidies up" the molecule and removes nucleotides that are not involved in protein production Figure 6.
Then, a sequence of adenine nucleotides called a poly-A tail is added to the 3' end of the mRNA molecule Figure 7. This sequence signals to the cell that the mRNA molecule is ready to leave the nucleus and enter the cytoplasm. What's next for the RNA molecule? More on transcription. How are polymerases different in prokaryotes and eukaryotes? How is bacterial transcription unique? How is transcription regulated?
Once an mRNA molecule is complete, that molecule can go on to play a key role in the process known as translation. During translation , the information that is contained within the mRNA is used to direct the creation of a protein molecule. In order for this to occur, however, the mRNA itself must be read by a special, protein-synthesizing structure within the cell known as a ribosome. Watch this video for a summary of eukaryotic transcription.
What are introns and exons? Key Concepts RNA replication transcription. Topic rooms within Genetics Close. No topic rooms are there. Browse Visually.
Other Topic Rooms Genetics. Student Voices. Creature Cast. Simply Science. Genetic Mutation. Functions and Utility of Alu Jumping Genes. Transposons: The Jumping Genes. DNA Transcription. What is a Gene? Colinearity and Transcription Units. Copy Number Variation. Copy Number Variation and Genetic Disease. Copy Number Variation and Human Disease.
Tandem Repeats and Morphological Variation. Chemical Structure of RNA. Eukaryotic Genome Complexity. RNA Functions. Citation: Clancy, S. Nature Education 7 1 The more researchers examine RNA, the more surprises they continue to uncover.
What have we learned about RNA structure and function so far? Aa Aa Aa. Figure 1. Figure Detail. Figure 2. Figure 3. Figure 4. Ribosomal RNA rRNA , which forms the structural and functional components of the ribosome, is present in bacterial and eukaryotic cells. In eukaryotic cells, it is present in the cytoplasm.
In eukaryotes, it's found in the nucleus and cytoplasm. Transfer RNA tRNA , which helps incorporate amino acids into growing polypeptide chains, is present in bacterial and eukaryotic cells. In eukaryotes, it's found in the cytoplasm. Figure 8. Figure 9. More and More RNAs. For instance, short RNAs are not only part of organelles like ribosomes and spliceosomes, but also of some enzymes.
For example, the enzyme telomerase , which adds nucleotides to the ends of chromosomes, is composed of a nucleotide RNA and several proteins. Juli Feigon at the University of California, Los Angeles, together with postdoctoral scholar Carla Theimer and graduate student Craig Blois, first solved the structure of an essential piece of this RNA by nuclear magnetic resonance spectroscopy Theimer et al. References and Recommended Reading Berget, S. Cell 20 , — Evans, R. Cell 12, — Holley, R. RNA contains the unmethylated form of the base thymine called uracil U Figure 6 , which gives the nucleotide uridine.
RNA performs a variety of functions in the cell. Most of the RNA, however, does not code for proteins.
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