Phosphate Group

4 Key excerpts on "Phosphate Group"

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  eBook - ePub

  The Chemical Biology of Phosphorus

  • Christopher T Walsh(Author)
  • 2020(Publication Date)
  • Royal Society of Chemistry

    (Publisher)

  6 analyze Todd's arguments and provide additional perspective 30 years on. Among the properties embedded in phosphate chemistry essential to biology are the following:

  1. DNA information retention from organism generation to generation requires ultrastable phosphodiester internucleotide bonds, that are nonetheless rapidly repairable when necessary.
  2. If life started via an RNA world then phosphodiesters were key covalent linkages stitching together bits of chemical information.
  3. Lipid membrane barriers define an inside and outside for cells and organisms and allow establishment of transmembrane electrochemical potentials. Phospholipid diester head groups , attached covalently to lipid tails, are the universal building blocks for biological membranes.
  4. To build skeletons strong enough to support large organisms, most notably mammals, calcium phosphate salts comprise the building block for bones and teeth
  5. Organisms constantly need energy supplies to survive. The energetics of life are built around phosphoric anhydride chemistry
  6. Regulation of information flow and signaling over different time regimes is dominated by two parallel signaling regimes involving phosphate chemistry : (a) a set of low molecular weight second messengers: cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), di-cyclic GMP, di-cyclic GMP–cAMP; (b) protein posttranslational phosphorylations.

  We take up each of these facets of Phosphate Group chemistry in biological contexts through the subsequent chapters of this book. Life is certainly more than phosphoryl group chemistry but no other element in the periodic table exhibits chemical properties that would allow life to be constructed by a phosphorus replacement. (Pentavalent arsenic has some replacement properties, but its esters are chemically labile in aqueous physiological media).

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  eBook - PDF

  Essentials of Inorganic Chemistry

  For Students of Pharmacy, Pharmaceutical Sciences and Medicinal Chemistry

  • Katja A. Strohfeldt(Author)
  • 2014(Publication Date)
  • Wiley

    (Publisher)

  Phosphate is an inorganic compound and is the salt of phosphoric acid. It can form organic esters with a variety of compounds and these are important in many biochemical processes. Phosphate has the empirical formula PO 4 3− . It is a tetrahedral molecule, where the central phosphorus atom is surrounded by four oxygen atoms (Figure 6.5). The phosphate ion PO 4 3− is the conjugated base of the hydrogen phosphate ion (HPO 4 2− ). HPO 4 2− is the conjugated base of the dihydrogen phosphate ion (H 2 PO 4 − ). The latter is the conjugated base of phosphoric acid (H 3 PO 4 ). A conjugated base is formed from an acid by the removal of a proton. This means that the conjugate base of an acid is this acid without a proton. An analogous definition applies to a conjugate acid. A conjugate base (of the acid) + H + → Acid A conjugate acid (of the base) → Base + H + In biological systems, phosphate is often found either as the free ion (inorganic phosphate) or as an ester after reaction with organic compounds (often referred to as organic phosphates). Inorganic phosphate (mostly denoted as P i ) is a mixture of HPO 4 2− and H 2 PO 4 − at physiological pH. 6.2.1 Adenosine phosphates: ATP, ADP and AMP Adenosine phosphates are organic-phosphate-containing compounds that are responsible for the energy flow in many biochemical processes in living cells. Adenosine phosphates consist of three parts: a sugar molecule (ribose) as the backbone, to which a nucleobase adenine and a varying number of Phosphate Groups are con- nected. Adenine is bonded to C-1 of the sugar, whilst the Phosphate Groups are connected to each other and then are attached to the C-5 atom of the ribose backbone. There is a series of adenosine phosphates depend- ing on the number of Phosphate Groups present. Adenosine triphosphate (ATP) contains three Phosphate Groups, whilst adenosine diphosphate (ADP) contains two and adenosine monophosphate (AMP) contains one Phosphate Group (Figure 6.6) [2].

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  eBook - PDF

  Phosphorus

  Chemistry, Biochemistry and Technology, Sixth Edition

  • D.E.C. Corbridge(Author)
  • 2016(Publication Date)
  • CRC Press

    (Publisher)

  921 11 Biophosphorus Chemistry Phosphorus biochemistry is dominated by two phosphate esters, namely ATP and DNA There are, however, many other P compounds (eg phosphoenzymes) which play a crucial role in metabolic processes Phosphorus has more known biochemical functions in the body than any other single mineral element If carbon compounds are regarded as the ‘building blocks’ of life, phosphorus must surely be regarded as the ‘site manager’ Important non-bio parallels between carbon chemis-try and phosphorus chemistry have been recognised in recent decades (Chapter 6) Metabolic processes can be defined as those processes whereby living organisms create and manufacture their own substance and obtain energy in order to function Biophosphorus compounds are involved in most of these Primary metabolic processes are those which evolve primary metabolites such as fats, carbohy-drates, proteins and nucleic acids which are common to all living species Metabolism involves very many reaction sequences, which are frequently cyclic and interacting These reactions are almost all enzyme-catalysed and they often employ special energy-carrying molecules In most biochemical reaction sequences, organic phosphate esters are involved, either as energy carriers, as coenzymes or as intermediates Many of these biochemical processes are common to a wide variety of life forms, although some are found only in restricted species of animals or plants Essential metabolic functions of inorganic phosphates include animal bone formation, and buff-ering action in urine, blood and other body fluids Metabolism consists essentially of catabolic and anabolic processes In catabolic processes (eg digestion) the nutrient fats, proteins and carbohydrates are broken down into simpler units, and much of the energy released is transferred to energy-carrying molecules, most of which contain P In anabolic or

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  eBook - ePub

  Organophosphorus Chemistry

  From Molecules to Applications

  • Viktor Iaroshenko(Author)
  • 2019(Publication Date)
  • Wiley-VCH

    (Publisher)

  10 Phosphorus in Chemical Biology and Medicinal Chemistry

  Marlon Vincent V. Duro Dana Mustafa Boris A. Kashemirov and Charles E. McKenna

  University of Southern California, Department of Chemistry, 840 Downey Way LJS 268, Los Angeles, CA, 90089‐0744, USA

  10.1 Phosphorus and Life: An Introduction

  The earth's crust, including its oceans, is approximately 16 km thick but consists of merely 0.04% by mass of the element phosphorus [1] . However, upon the examination of living organisms, we find that phosphorus is present in many of the molecules that play an essential role in living processes and that this element constitutes 2–4% of the dry weight of living cells [2] . It is also the sixth most abundant element in the human body (1.1% by mass, after the four basic organic elements and calcium) [3] . In fact, life is truly built around phosphorus, which is evident in the fact that the phosphorus content of an environment essentially dictates whether life can be sustained within it or not [1 , 4 , 5 ]. To illustrate just how crucial phosphorus is to our lives, consider the fact that each day, one person's metabolic process results in a turnover of several kilograms of adenosine triphosphate (ATP , 1, Figure 10.1 ) [6] .

  Figure 10.1 A few examples of organophosphorus compounds in biological systems.

  However, it is not simply just the availability of the different elements that governs the composition of organisms. Rather, it is the “fitness” – the distinct collection of properties that allows these elements to fulfill their roles in the organism. Thus, Wald attributed the biological selection of P to the facts that (i) it forms more open and generally weaker bonds than its congeners in the second period of the periodic table, O and N, (ii) it possesses 3d orbitals, allowing for the expansion of its valences beyond four, and (iii) it is capable of forming multiple bonds, which is also characteristic of the elements C, N, and O [7]

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