Scientists Say: RNA | Science News for Students

Scientists Say: RNA

This is a molecule that helps cells carry out the instructions in DNA
Oct 21, 2019 — 6:30 am EST
An illustration of RNA

RNA helps cells make proteins from the instructions in DNA. This molecule has other roles in the body too. For instance, RNA can turn genes off or on.

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RNA (noun, “R-N-A”)

This is short for ribonucleic (Rye-bo-nu-CLAY-ic) acid. RNA is a molecule that helps cells carry out the instructions in DNA. These instructions are found in sections of DNA called genes. They tell cells how to make proteins.  Proteins are molecules that carry out important cell functions like converting food to energy and fighting infection.

Both DNA and RNA are made up of building blocks called nucleotides (NU-klee-oh-tydz). The order of these nucleotides in a gene makes up a code. This code tells the body’s cells what kinds of proteins to make. That’s where RNA comes in. Inside a cell’s nucleus, one type of RNA copies the information in the DNA code. This RNA, called messenger RNA, travels to a structure called a ribosome (RYE-bo-zome). The ribosome itself is made up of RNA called ribosomal RNA, which helps “read” the code in the messenger RNA. This code tells another type of RNA, called transfer RNA, to bring the pieces needed to make the proteins to the ribosome. It’s important that the RNA exactly copy the information in the DNA code. If it makes a mistake, the cell might not make the correct protein. In some cases, this can cause serious illness or other harmful effects.  

Scientists are still learning about different types of RNA and their roles in the body. Some RNA can turn genes off and on and make modifications to proteins. Others may be bad actors that help tumors spread.  

In a sentence

The genetic code in some viruses, like measles and influenza, is made of RNA, not DNA.

Check out the full list of Scientists Say.

Power Words

(more about Power Words)

cell     The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall. Depending on their size, animals are made of anywhere from thousands to trillions of cells. Most organisms, such as yeasts, molds, bacteria and some algae, are composed of only one cell.

DNA     (short for deoxyribonucleic acid) A long, double-stranded and spiral-shaped molecule inside most living cells that carries genetic instructions. It is built on a backbone of phosphorus, oxygen, and carbon atoms. In all living things, from plants and animals to microbes, these instructions tell cells which molecules to make.

messenger RNA     A type of genetic material that is copied from DNA. It carries the instructions for building a cell’s proteins.

molecule     An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O2); water is made of two hydrogen atoms and one oxygen atom (H2O).

nucleotides     The four chemicals that, like rungs on a ladder, link up the two strands that make up DNA. They are: A (adenine), T (thymine), C (cytosine) and G (guanine). A links with T, and C links with G, to form DNA. In RNA, uracil takes the place of thymine.

protein     A compound made from one or more long chains of amino acids. Proteins are an essential part of all living organisms. They form the basis of living cells, muscle and tissues; they also do the work inside of cells. Among the better-known, stand-alone proteins are the hemoglobin (in blood) and the antibodies (also in blood) that attempt to fight infections. Medicines frequently work by latching onto proteins.

RNA     A molecule that helps “read” the genetic information contained in DNA. A cell’s molecular machinery reads DNA to create RNA, and then reads RNA to create proteins.

transfer RNA     (tRNA) A type of RNA (ribonucleic acid) molecule that a cell uses to read a section of messenger RNA. This takes place during the production of a cellular protein.