Ribose

Type of simple sugar, or carbohydrate, with molecular formula C₅H₁₀O₅. Ribose (specifically d-ribose) is a crucial component of ribonucleic acid (RNA). RNA serves as a messenger moleculeCollection of atoms held together by chemical bonds into a discrete, finite structure. One way molecules are represented is by a chemical formula where symbols for the elements are used to indicate the types of atoms present and subscripts are used to indicate the relative numbers of atoms. For example,, copying genetic instructions from the DNA molecule (deoxyribonucleic acid) and delivering them to molecular factories within the cell called ribosomes that read the RNA to build specific proteins needed to carry out life processes. It is also an essential component of adenosine triphosphate (ATP), which supplies energy to living cells.

Similar to DNA, RNA also carries information for how to build and operate a living organism, and many researchers think it evolved first and was later replaced by DNA. This is because RNA molecules have capabilities that DNA lacks. RNA can make copies of itself independently from other molecules, and it can also initiate or speed up chemical reactions as a catalystChemicals that are not consumed in a reaction, but, which speed up the reaction rate. Catalysts aid to form a transition state which is lower in energy than the transition state without the catalyst (essentially decreasing activation energy). Since the barrier to the reaction is lower, the reaction rate increases. The discovery of sugar molecules in meteorites gives some evidence to support the possibility that RNA coordinated the machinery of life before DNA. As explained by Danny Glavin, a co-author of the study at NASA Goddard, “The sugar in DNA (2-deoxyribose) was not detected in any of the meteorites analyzed in this study. This is important since there could have been a delivery bias of extraterrestrial ribose to the early Earth which is consistent with the hypothesis that RNA evolved first.”