Aquatic Photosynthesis

Aquatic Photosynthesis: (Second Edition)

Paul G. Falkowski
John A. Raven
Copyright Date: 2007
Edition: STU - Student edition
Pages: 512
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  • Book Info
    Aquatic Photosynthesis
    Book Description:

    Aquatic Photosynthesis is a comprehensive guide to understanding the evolution and ecology of photosynthesis in aquatic environments. This second edition, thoroughly revised to bring it up to date, describes how one of the most fundamental metabolic processes evolved and transformed the surface chemistry of the Earth. The book focuses on recent biochemical and biophysical advances and the molecular biological techniques that have made them possible.

    In ten chapters that are self-contained but that build upon information presented earlier, the book starts with a reductionist, biophysical description of the photosynthetic reactions. It then moves through biochemical and molecular biological patterns in aquatic photoautotrophs, physiological and ecological principles, and global biogeochemical cycles. The book considers applications to ecology, and refers to historical developments. It can be used as a primary text in a lecture course, or as a supplemental text in a survey course such as biological oceanography, limnology, or biogeochemistry.

    eISBN: 978-1-4008-4972-7
    Subjects: Aquatic Sciences, Biological Sciences

Table of Contents

  1. Front Matter
    (pp. i-vi)
  2. Table of Contents
    (pp. vii-viii)
  3. Preface to the Second Edition
    (pp. ix-x)
    PGF and JAR
  4. Preface to the First Edition
    (pp. xi-xvi)
    PGF and JAR
  5. 1 An Introduction to Photosynthesis in Aquatic Systems
    (pp. 1-43)

    Photosynthesis is the biological conversion of light energy to chemical bond energy that is stored in the form of organic carbon compounds. Approximately 45% of the photosynthesis on Earth each year occurs in aquatic environments (Falkowski 1994; Field et al. 1998). However, because we live on land and the aggregate biomass of aquatic plants amounts to less than 1% of the total photosynthetic biomass on our planet, terrestrial plants are much more a part of the human experience (Table 1.1). Consequently, the role and importance of aquatic photosynthetic organisms in shaping the ecology and biogeochemistry of Earth often is not...

  6. 2 Light Absorption and Energy Transfer in the Photosynthetic Apparatus
    (pp. 44-80)

    Photosynthesis begins with the absorption of light and the transfer of its energy to special structures, called reaction centers, where the energy is used in electrical charge separation. These three processes—absorption, energy transfer, and primary charge separation—constitute the so-called light reactions of photosynthesis, and are fundamentally similar in all photosynthetic organisms. An understanding of the light reactions requires some understanding of the nature of light itself, the process of light absorption by atoms and molecules, the relationship between light absorption and molecular structure, and the concept of energy transfer between homogeneous and heterogeneous molecules. In this chapter we...

  7. 3 The Photosynthetic Light Reactions
    (pp. 81-117)

    The absorption of light by photosynthetic pigments does not, in and of itself, lead to a chemical reaction; cooked spinach is green but quite photochemically dead. The search for the mechanism of the photochemical reactions has been and remains a major focus of research in photosynthesis, and we will present these ideas from conceptual as well as historical perspectives. Before doing so, however, let us first briefly define the term light reaction.

    A chemical reaction transforms one or more substrates to one or more products by altering electronic bonding configurations within atoms or molecules. Changes in bonding configurations usually are...

  8. 4 Photosynthetic Electron Transport and Photophosphorylation
    (pp. 118-155)

    The main role of the photosynthetic electron transport chain is to provide chemical reductants used to assimilate inorganic carbon, and chemical energy that is used to sustain metabolic activity of the organism. While the reaction centers are the engines of the photosynthetic apparatus, the drive train consists of a highly organized structure that mediates the transfer of electrons and protons. In converting the energy of light to chemical energy, the electrons extracted from water are used to transiently reduce molecules in the electron transport chain. The protons produced in the photochemical oxidation of water and transported by other reactions represent...

  9. 5 Carbon Acquisition and Assimilation
    (pp. 156-200)

    The NADPH and ATP generated by the electron transport chain in the thylakoid membranes couple the light reactions to carbon fixation and, ultimately, to cell growth. For a microalga growing photoautotrophically, approximately 95% of the NADPH and more than 60% of the photosynthetically generated ATP are used to assimilate and reduce inorganic carbon. Although there are a variety of carbon-fixing pathways in anoxygenic photoautotrophs, in oxygenic photoautotrophs the pathway for inorganic carbon fixation invariably involves the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). As we shall explain shortly, Rubisco can use only $ CO_{2} $ as a substrate. Hence, inorganic carbon uptake must ultimately lead...

  10. 6 The Molecular Structure of the Photosynthetic Apparatus
    (pp. 201-236)

    As described in the preceding chapters, photosynthesis involves light harvesting, primary charge separation in both PSII and PSI, electron transport, ATP and NADPH formation, carbon fixation, and regeneration of substrates in the Calvin-Benson cycle. The biophysical and biochemical integration of photosynthetic processes requires the synthesis and coordinated assembly of numerous proteins, lipids, prosthetic groups, and cofactors. The synthesis and assembly of all the molecules that make up the photosynthetic apparatus are controlled and directed by the genetic machinery of the organism. Significant advances in understanding photosynthetic processes, evolutionary relationships, and trends among photosynthetic organisms, as well as the mechanisms and...

  11. 7 Photosynthesis in Continuous Light
    (pp. 237-277)

    Ultimately, the complex web of reactions that leads to photosynthetic carbon fixation must function in a coordinated fashion. Among other things, coordination means that light absorption by PSII and PSI is balanced so that electron transport between the two photosystems is optimized, the flux of reductant and ATP generated by the electron transport system is provided in the proper ratios and is sufficient to support the maximum rate of carbon fixation for a given light environment, and excess excitation energy is dissipated to prevent or minimize damage to the photosynthetic apparatus. Because solar radiation is broadband, continuous, and continuously changing,...

  12. 8 Making Cells
    (pp. 278-318)

    The principal products of the photosynthetic reactions are sugars, reductant, ATP, and molecular $ O_{2} $ . In all photoautotrophs, these products are themselves substrates for biosynthetic reactions. The synthesis of many essential cellular components, such as amino and nucleic acids, requires elements other than carbon, hydrogen, and oxygen. For example, oxidized (and environmentally more stable) forms of nitrogen (usually $ NO_{3}^{-} $ ) or sulfur (as sulfate, $ SO_{4}^{2-} $ ) must be reduced to the level of ammonium ( $ NH_{4}^{+} $ ) or sulfide ( $ (-SH) $ ) to serve the purposes of most biosynthetic reactions. These reductions come at the expense of electrons derived from photosynthetically energized...

  13. 9 Photosynthesis and Primary Production in Nature
    (pp. 319-363)

    The natural world is never truly in steady state. Sometimes, however, patterns or cycles in some environmental variables emerge, leading to a degree of predictability (Powell and Steele 1995). One of the more obvious examples is solar irradiance. To first order, the light reaching the surface of the Earth is given by the path of the sun as it crosses the sky. This path determines the total number of hours of daylight and the maximum incident solar radiation for each point on the globe. Superimposed on this astronomically predictable pattern are chaotic and stochastic variations in light related to meteorological...

  14. 10 Aquatic Photosynthesis in Biogeochemical Cycles
    (pp. 364-410)

    In 1830, the British geologist Charles Lyell (whom we briefly discussed in chapter 1) carefully elaborated on a theory to explain geological formations and the distribution of fossils. That theory, which came to be called uniformitarianism, was “an attempt to explain the former changes in the Earth’s surface by reference to causes now in operation.” Thus, such phenomena as erosion, volcanic eruptions, glaciations, floods, and earthquakes have, over long periods of time, produced mountains, deltas, outwash plains, and island masses. The theory of uniformitarianism provided, for the first time, a rational framework through which to interpret the geological history of...

  15. References
    (pp. 411-464)
  16. Index
    (pp. 465-484)