<P> The two nucleic acids, DNA and RNA, are polymers of nucleotides . Each nucleotide is composed of a phosphate attached to a ribose or deoxyribose sugar group which is attached to a nitrogenous base . Nucleic acids are critical for the storage and use of genetic information, and its interpretation through the processes of transcription and protein biosynthesis . This information is protected by DNA repair mechanisms and propagated through DNA replication . Many viruses have an RNA genome, such as HIV, which uses reverse transcription to create a DNA template from its viral RNA genome . RNA in ribozymes such as spliceosomes and ribosomes is similar to enzymes as it can catalyze chemical reactions . Individual nucleosides are made by attaching a nucleobase to a ribose sugar . These bases are heterocyclic rings containing nitrogen, classified as purines or pyrimidines . Nucleotides also act as coenzymes in metabolic - group - transfer reactions . </P> <P> Metabolism involves a vast array of chemical reactions, but most fall under a few basic types of reactions that involve the transfer of functional groups of atoms and their bonds within molecules . This common chemistry allows cells to use a small set of metabolic intermediates to carry chemical groups between different reactions . These group - transfer intermediates are called coenzymes . Each class of group - transfer reactions is carried out by a particular coenzyme, which is the substrate for a set of enzymes that produce it, and a set of enzymes that consume it . These coenzymes are therefore continuously made, consumed and then recycled . </P> <P> One central coenzyme is adenosine triphosphate (ATP), the universal energy currency of cells . This nucleotide is used to transfer chemical energy between different chemical reactions . There is only a small amount of ATP in cells, but as it is continuously regenerated, the human body can use about its own weight in ATP per day . ATP acts as a bridge between catabolism and anabolism . Catabolism breaks down molecules, and anabolism puts them together . Catabolic reactions generate ATP, and anabolic reactions consume it . It also serves as a carrier of phosphate groups in phosphorylation reactions . </P> <P> A vitamin is an organic compound needed in small quantities that cannot be made in cells . In human nutrition, most vitamins function as coenzymes after modification; for example, all water - soluble vitamins are phosphorylated or are coupled to nucleotides when they are used in cells . Nicotinamide adenine dinucleotide (NAD), a derivative of vitamin B (niacin), is an important coenzyme that acts as a hydrogen acceptor . Hundreds of separate types of dehydrogenases remove electrons from their substrates and reduce NAD into NADH . This reduced form of the coenzyme is then a substrate for any of the reductases in the cell that need to reduce their substrates . Nicotinamide adenine dinucleotide exists in two related forms in the cell, NADH and NADPH . The NAD / NADH form is more important in catabolic reactions, while NADP / NADPH is used in anabolic reactions . </P>

What is the name of the form of chemical energy in the body that can be used by all cells