The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
Adenosine triphosphate is an organic compound that serves as a source of energy for living organisms, and assists them in carrying out a wide variety of important functions. It is sometimes referred to as the cell's currency of energy exchange. The compound consists of a substituted purine base (6-aminopurine) linked to a five carbon sugar (ribose) that is triply phosphorylated. In activities requiring energy assist, hydrolysis converts ATP to adenosine diphosphate (ADP) and phosphate by removing the terminal phosphate group. Because the total free energy of the products of this chemical reaction (ADP and phosphate) is less than that of ATP, energy is released. The liberated energy can be harnessed and used by living cells. Energy-requiring processes that make use of energy available in ATP include synthesis of proteins, fats, polysaccharides and nucleic acids. ATP is also used to accomplish mechanical work by assisting muscle contraction in animals or the movement of cilia and flagella in microscopic organisms. Many important physiological functions require ATP for osmotic work in which ions or metabolites are transported through membranes against a concentration gradient. Nerve conduction, kidney function, and secretion of hydrochloric acid in the stomach are all examples of processes thus made possible. In plants, photosynthesis is assisted by the conversion of light energy into chemical energy in the form of ATP in a process called photophosphorylation. The ATP is used to drive energy-requiring synthesis of sugars and starch.