Unity and Diversity in Biochemistry: An Introduction to Chemical Biology

By Marcel Florkin; T. Wood | Go to book overview

INTRODUCTION

THE biosphere is the seat of a continuous transformation of matter and energy. Despite influences tending constantly to convert the chemical elements into the highly oxidized state characteristic of inanimate matter, this activity maintains the living material and replaces it continuously throughout its more or less prolonged, but finite, life-span. The metabolism of the organisms which make up the biosphere shows certain general characteristics common to all organisms, besides those applying only to particular types or classes. The organism makes pyrophosphate bonds ready for the performance of various types of cellular work by means of a chemical machine whose essential character is everywhere the same. This machine can be fed by the chief types of chemical structure which are present to a high proportion in all types of protoplasm: sugars, fatty acids and amino acids. This applies also to those organisms which receive their energy from outside the biosphere and are called autotrophes (see Part Five). In the autotrophes, which can build up organic macromolecules from simple inorganic materials, and in the heterotrophes (organisms depending on a supply of protoplasm from another organism, which can be broken down), the supply of cellular nutrients (sugars, fatty acids and amino acids) in most cases requires a corresponding breakdown of macromolecules formed by the association of these nutrients. Here we have an important generalization which has already been mentioned by Herbert Spencer in his Principles of Biology. The macromolecules which form the plastic structure predominant in living beings should in fact have a certain stability, which will allow them to act as a reserve for nutritional purposes and which will assure the persistence of form, despite what we now know to be a dynamic state which, in the course of time, renews these molecules more or less quickly, completely or partially. On the other hand these polymers should be endowed with a certain instability permitting them to deliver up the whole of their monomer content to the turnover of cellular nutrients when protoplasm is acting as food. This, we know now, is not due to the instability of the macromolecules but to the presence of specific enzymes, the hydrolases, which can cleave peptide, oside and ester bonds. There are not very many different kinds of hydrolases, but they are found in extremely diverse locations and employed in a variety of different ways; in fact their study is of interest both to the biochemist and to the comparative physiologist. The final result of their action is the liberation of fatty acids, sugars and amino acids, which become available to the metabolism of the cell and form its actual nutrient.

-179-

Notes for this page

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items
Notes
Cite this page

Cited page

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA 8, MLA 7, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Note: primary sources have slightly different requirements for citation. Please see these guidelines for more information.

Cited page

Bookmark this page
Unity and Diversity in Biochemistry: An Introduction to Chemical Biology
Table of contents

Table of contents

  • Title Page iii
  • Contents v
  • List of Abbreviations vii
  • Translator's Preface ix
  • Introduction xi
  • Part One xv
  • Chapter I - The Biosphere 1
  • Chapter II - Constituents of the Biosphere 7
  • References 14
  • References 24
  • References 30
  • References 37
  • References 43
  • References 56
  • Chapter III - Modes of Linkage by Covalent Bonds 57
  • References 60
  • References 62
  • References 77
  • References 82
  • Chapter IV - Macromolecules 83
  • References 85
  • References 93
  • References 107
  • References 111
  • Part Two - Enzymes and Biochemical Energetics 129
  • Chapter I - General Principles of Biochemical Energetics 131
  • References 150
  • Chapter II - Enzymes 151
  • References 176
  • Part Three - Chemical Reactions in the Biosphere 177
  • Introduction 179
  • Chapter I - Destructive and Non-Destructive Methods in Modern Biochemistry 181
  • References 182
  • References 184
  • References 185
  • Chapter II - Priming Reactions 186
  • References 197
  • References 199
  • References 207
  • References 209
  • References 223
  • Chapter III - Biosyntheses 229
  • Part Four - Topobiochemistry and Cellular Regulation 271
  • Chapter I - Cellular Topochemistry 273
  • Conclusions 280
  • References 280
  • Chapter II - Cellular Regulation 282
  • References 286
  • Part Five - Biochemical Diversity 287
  • Chapter I - Some Aspects of Biochemical Diversity 289
  • References 303
  • Chapter II - The Inheritance of Biochemical Characteristics 304
  • References 316
  • Chapter III - Biochemistry and Taxonomy 317
  • References 332
  • Chapter IV - Biochemical Evolution 333
  • References 335
  • References 345
  • Part Six - The Metabolism of the Biosphere 347
  • Introduction 349
  • Chapter I - Entry into the Biosphere 351
  • References 365
  • Chapter II - Departure from the Biosphere 366
  • References 370
  • Chapter III - The Cycles 371
  • References 380
  • Index 381
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this book

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen
Items saved from this book
  • Bookmarks
  • Highlights & Notes
  • Citations
/ 402

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA 8, MLA 7, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Search by... Author
    Show... All Results Primary Sources Peer-reviewed

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.