Adenosine diphosphate, function structure

Adenosine triphosphate, coupled reactions and. 1128-1129 function of, 157, 1127-1128 reaction with glucose, 1129 structure of, 157, 1044 S-Adenosylmethionine, from methionine, 669 function of, 382-383 stereochemistry of, 315 structure of, 1045 Adipic acid, structure of, 753 ADP, sec Adenosine diphosphate Adrenaline, biosynthesis of, 382-383 molecular model of, 323 slructure of, 24... 

Phosphorus has more known functions in the animal body than any other mineral element. Together with calcium, phosphorus plays a major role in the formation of bones and teeth, as well as eggshells. It is a component of nucleic acids, which control cell multiplication, growth and differentiation. In combination with other elements, phosphorus has a role in the maintenance of cellular osmotic pressure and the acid-base balance. Energy transfer processes in all living cells involve interconversion of the phosphate-containing nucleotides, adenosine diphosphate (ADP) and ATP, and thus phosphorus participates in all biological events. Other roles include its presence in phospholipids, where it functions in cell-wall structure, fatty acid transport and protein as well as amino acid formation. 

All living cells contain adenosine triphosphate, ATP, which consists of adenine, ribose and triphosphate units. The structure of ATP is shown below. Hydrolysis results in the loss of a phosphate group and converts ATP to ADP (adenosine diphosphate), releasing energy which is used for functions such as cell growth and muscle movement. In a simplified... 

A variety of enzyme cofactors serving a wide range of chemical functions include adenosine as part of their structure (Fig. 8-41). They are unrelated structurally except for the presence of adenosine. In none of these cofactors does the adenosine portion participate directly in the primary function, but removal of adenosine generally results in a drastic reduction of cofactor activities. For example, removal of the adenine nucleotide (3 -phosphoadenosine diphosphate) from acetoacetyl-... 

In addition to these we need to mention a small group of metabolites that belong structurally with the building blocks of nucleic acids but which have major metabolic functions that are quite separate from their relationship to nucleic acids. These are the adenosine phosphates two of these, adenosine 5 -triphosphate and adenosine 5 -diphosphate, participate in many metabolic reactions (more, indeed, than any other substance, aside from water) a third, adenosine 5 -monophosphate, participates in relatively few reactions but affects many enzymes as an inhibitor or as an activator. These names are cumbersome for everyday use and biochemists refer to them nearly aU of the time as ATP, ADP, and AMP, respectively. In animals, the ATP needed for driving all the functions of the cell is generated in small compartments of cells called mitochondria. For the purposes of this book we shall not need to know any details of how mitochondria fulfill their functions, but we do need to know that they exist, because we shall meet them again in a quite different context it turns out that in most organisms mitochondria contain small amounts of their own DNA, and this allows some special kinds of analyses. Adenosine, the skeleton from which ATP, ADP, and AMP are built, has a separate importance as one of the four bases that define the sequence of DNA. 

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