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RNA

life science Maturity 9-11 Vital Level 3 Next article →

RNA is a vital molecule found in almost all living things. It is a type of nucleic acid, just like DNA. These molecules are among the four major building blocks of life. RNA is built from long chains of small parts called nucleotides. Each nucleotide has a sugar called ribose and a phosphate group. The chain also uses four different bases: adenine (A), guanine (G), cytosine (C), and uracil (U).

RNA chemical structure
RNA chemical structure

While DNA is usually a long double strand, RNA is often a single strand. This single strand can fold back on itself to make special shapes. These shapes help it do many different jobs inside a cell.

Piwi-siRNA-basepairing
Piwi-siRNA-basepairing

RNA works in many ways to keep a cell running. One main job is helping to build proteins. This process happens in a few clear steps. First, messenger RNA (mRNA) carries instructions from the DNA to a ribosome. The ribosome is a tiny factory in the cell. Next, transfer RNA (tRNA) molecules act like delivery trucks. They bring specific amino acids to the ribosome. Then, ribosomal RNA (rRNA) helps link those amino acids together into a protein chain.

Translation of mRNA
Translation of mRNA

This beautiful teamwork allows the cell to create the proteins it needs to live.

Scientists have learned a lot about how these molecules behave. Some RNA molecules are even tools that can cause chemical changes. These special tools are called ribozymes. One amazing example is the ribosome itself. The active part of the ribosome that builds proteins is made entirely of RNA.

50S-subunit of the ribosome 3CC2
50S-subunit of the ribosome 3CC2

This shows that RNA is much more than just a messenger. It can also act like an enzyme to drive important biological reactions. This discovery changed how we understand the very basics of life.

There are many different kinds of RNA with specific names. Most RNA in a cell is actually rRNA, which helps make ribosomes. There are also small RNAs, like microRNA (miRNA) and small interfering RNA (siRNA). Some RNAs are very long, while others are quite short. For example, a tRNA molecule is usually about 80 nucleotides long.

R Holley
R Holley

Scientists like Robert W. Holley have done important work studying these molecules. Even though there are many types, they all share the same basic building blocks. Some RNA can even be modified with new parts to help them work better.

Learning about RNA helps us understand the history of our world. Many scientists believe in an "RNA world" theory. This idea suggests that early in Earth's history, RNA did everything. It stored genetic information and acted as a tool for chemical reactions. This was likely true before DNA and proteins even existed.

Full length hammerhead ribozyme
Full length hammerhead ribozyme

Today, DNA holds most of our information, but RNA is still the star of the show. Even some viruses use RNA as their main way to store their genetic code. It is a molecule that connects the past of life to the present.

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🖼️ Images & Media (10)
File:Pre-mRNA-1ysv-tubes.png
Pre-mRNA-1ysv-tubes.png
File:Piwi-siRNA-basepairing.png
Piwi-siRNA-basepairing.png
File:50S-subunit of the ribosome 3CC2.png
50S-subunit of the ribosome 3CC2.png
File:RNA chemical structure.GIF
RNA chemical structure.GIF
File:Ciliate telomerase RNA.JPG
Ciliate telomerase RNA.JPG
File:Full length hammerhead ribozyme.png
Full length hammerhead ribozyme.png
File:Translation of mRNA.svg
Translation of mRNA.svg
File:Synthesis of Pseudouridine.svg
Synthesis of Pseudouridine.svg
File:Double-stranded RNA.gif
Double-stranded RNA.gif
File:R Holley.jpg
R Holley.jpg
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