Photochemistry of Vision


Book Description

Radiation can only affect matter if absorbed by it. Within the broad range of 300-1000 nm, which we call "the visible", light quanta are energetic enough to produce excited electronic states in the atoms and molecules that absorb them. In these states the molecules may have quite different properties from those in their dormant condition, and reactions that would not otherwise occur become possible. About 80 % of the radiant energy emitted by our sun lies in this fertile band, and so long as the sun's surface temperature is maintained at about 6000° C this state of affairs will continue. This and the transparency of our atmosphere and waters have allowed the generation and evolution of life. Before life began the atmosphere probably also transmitted much of the solar short-wave radiation, but with the rise of vegetation a new product - oxygen - appeared and this, by a photochemical reaction in the upper atmosphere, led to the ozone layer that now protects us from the energetic "short-wave" quanta that once, perhaps, took part in the generation of life-molecules. Light is an ideal sensory stimulus. It travels in straight lines at great speed and, consequently, can be made to form an image from which an animal can make "true", continuous and immediate assessments of present and impending events.




Photochemistry of Vision


Book Description




Biochemistry of Vision


Book Description

Biochemistry of Vision provides information pertinent to vision biochemistry. This book discusses the biochemical information derived primarily from studies on nonocular tissues and describes the biochemical reactions related to the function of the retina and pigmented epithelium. Organized into 16 chapters, this book begins with an overview of the visual system and the structure of the vertebrate eye. The text then proceeds with a discussion of photoreceptor, which has a highly membranous structure. Other chapters cover a brief discussion of several topics, including biomembranes, photochemistry, spectral properties of retinal isomers, and the photochemical properties of the chromophore of rhodopsin. This book discusses as well the properties and intramembrane disposition of rhodopsin. The final chapter deals with the biochemistry of photoreceptor disorders and summarizes the basic knowledge on neurotransmitters and electrophysiology in the retina. This book is intended for ophthalmologists and medical students who are interested in the molecular aspects of photoreceptor diseases.




Photochemistry of Vision


Book Description

Radiation can only affect matter if absorbed by it. Within the broad range of 300-1000 nm, which we call "the visible", light quanta are energetic enough to produce excited electronic states in the atoms and molecules that absorb them. In these states the molecules may have quite different properties from those in their dormant condition, and reactions that would not otherwise occur become possible. About 80 % of the radiant energy emitted by our sun lies in this fertile band, and so long as the sun's surface temperature is maintained at about 6000° C this state of affairs will continue. This and the transparency of our atmosphere and waters have allowed the generation and evolution of life. Before life began the atmosphere probably also transmitted much of the solar short-wave radiation, but with the rise of vegetation a new product - oxygen - appeared and this, by a photochemical reaction in the upper atmosphere, led to the ozone layer that now protects us from the energetic "short-wave" quanta that once, perhaps, took part in the generation of life-molecules. Light is an ideal sensory stimulus. It travels in straight lines at great speed and, consequently, can be made to form an image from which an animal can make "true", continuous and immediate assessments of present and impending events.







Webvision


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Photochemistry of Vision


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Visual Pigments in Man (Classic Reprint)


Book Description

Excerpt from Visual Pigments in Man Lecturer the University of Liverpool has in some ways broken with tradition. For they have turned from the succession of giants to a man of ordinary stature and bestowed this distinction upon one who was neither a colleague of Sherrington nor his pupil, nor is even a specialist as to brain or spinal cord. Whatever may be thought of their choice of man, however, it cannot be doubted that the organisation of the retina is a most appropriate topic with which to commemorate what Sherrington stood for in scientific thought. For, as he clearly realized, the retina is a self-contained and exquisitely organized outgrowth Of the central nervous system, and nowhere is the relation between neural interaction and sensory perception more clearly displayed. But the wider I paint the sweep of my subject, the narrower will appear the treatment I have given it. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.




Basic Principles of Organic Chemistry


Book Description

Introduction what is organic chemistry all about?; Structural organic chemistry the shapes of molecules functional groups; Organic nomenclature; Alkanes; Stereoisomerism of organic molecules; Bonding in organic molecules atomic-orbital models; More on nomenclature compounds other than hydrocarbons; Nucleophilic substitution and elimination reactions; Separation and purification identification of organic compounds by spectroscopic techniques; Alkenes and alkynes. Ionic and radical addition reactions; Alkenes and alkynes; Oxidation and reduction reactions; Acidity or alkynes.




Duplicity Theory of Vision


Book Description

This book chronicles the development of three classic theories within vision research, from the 17th century to today, focusing on duplicity theory.