Products of the Enzymic Degradation of Starch and Glycogen1

Myrbäck, Karl

doi:10.1016/s0096-5332(08)60032-6

Cited by 26 publications

(3 citation statements)

References 56 publications

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“…The Aspergillus amylases are of the alpha type. The student is referred to the excellent reviews of Hopkins (1946) and Myrback (1948) for critical summaries of amylase activity. Amylase is widely distributed among the fungi but is not universal.…”

Section: Of Enzymesmentioning

confidence: 99%

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Physiology of the fungi [by] Virgil Greene Lilly [and] Horace L. Barnett.

Lilly¹

1951

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PHYSIOLOGY OF THE FUNGI previous knowledge. Organization and interpretation of facts are equally as important as the experimentation which reveals them.The fungi as a group are highly responsive to their environment and are thus excellent test organisms for inquiring into the secrets of nature.Nature always answers correctly the questions we ask, and, in this sense, no experiment is a failure, although we may fail to ask the question we intended, or we may misunderstand the answer given. Infinite care is required to frame a question so that a definite answer may be obtained. By observing fungi in nature we are limited to questions asked by nature.Commonly, the environmental and nutritional factors are so complex that the influence of a single variable cannot be evaluated. By controlling the conditions under which a fungus is placed in the laboratory it is possible to ask questions of great precision. Indeed, the number and scope of the questions which we may ask fungi are limited only by the present-day techniques and the curiosity of the investigator.Since most of our knowledge of the physiology of the fungi has been gained from laboratory investigations, the experimental approach will be emphasized in the discussions which follow. However, this choice is not meant to minimize the importance of and need for critical observations in nature.By emphasizing the results of careful laboratory research, we are better able in the following chapters to present the facts necessary for an understanding of the vital principles of fungus physiology, and also to show that these principles, theories, and hypotheses are founded upon experimental evidence. FUNGUS PHYSIOLOGY IN RELATION TO OTHER SCIENCESPhysiology is that branch of science which deals with the life processes or the activities of organisms. The activities of the whole organism or of any of its parts may be hmited by its form or structure. Both the activity and the form of an individual are determined to a great extent by its genetic constitution and are modified by the environment to which the organism is exposed. Physiology, therefore, is not an independent subject.An understanding of physiological principles is based, in part, upon facts and theories from many other fields of science, such as chemistry, physics, anatomy, cytology, bacteriology, and genetics. Many of the physiological principles which have been established for one group of organisms apply equally well to other groups. The vitamins essential to the normal growth of the fungi are the same as those required by man, animals, and the higher plants. The general functions of these vitamins appear to be the same in all organisms. The difference in the vitamin requirements seems to lie in the different abilities of these groups of organisms (or individuals within the group) to synthesize these necessary compounds. As Schopfer (1943) has pointed out, the The life processes of the fungi involve numerous chemical transformations.Living organisms make and use special organic catalysts, enzymes, which control ...

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Section: Of Enzymesmentioning

confidence: 99%

“…Fungus amylases are used to replace malt amylase for the saccharification of starch, Myrback (1948) is of the opinion that amylase from A.…”

Section: Metabolic Products 275mentioning

confidence: 99%

Physiology of the fungi [by] Virgil Greene Lilly [and] Horace L. Barnett.

Lilly¹

1951

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“…An important consideration is the type of attack characterizing the cane-leaf amylase. The concept of random attack has been widely held, based upon an enzyme's equal preference for nearly all of the 1 -* 4 linkages (18). Only those linkages adjacent to the polymer ends and branch points were considered more resistant.…”

Section: Significance Of Amylase Action In Canementioning

confidence: 99%

The Action Pattern of Sugarcane-Leaf Amylase

Alexander¹

1967

JAUPR

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The action pattern of sugarcane leaf amylase was investigated by paper chromatographic techniques. The enzyme was extracted with water from lyophilized leaf tissues, and precipitated by ammonium sulfate between 48- and 60-percent saturation. Aliquots were removed from enzyme-starch digests and inactivated in boiling water at intervals ranging from 5 minutes to 72 hours. Samples were spotted on Whatman No. 1 filter paper, irrigated with butanol-pyridine-water (6:4:3, v/v), and products identified by the silver nitrate technique. The initial and only major product was glucose. No maltose was detected, and oligosaccharides appeared only under conditions of excessively high enzyme concentration or prolonged reaction period. Preparations which appeared to contain distinct amylases on the basis of solubility and pH optima produced only glucose. Substrates hydrolyzed included soluble potato starch, cornstarch, amylose, amylopectin, and glycogen. Glucose was the lone product in each instance. Inulin was not attacked. Maltose was not affected by the enzyme preparation. Glucose produced by enzyme action on starch remained stable. A secondary sugar was formed after invertase preparation was introduced into the digest. This possibly represents an epimerase action upon the newly liberated glucose, but evidence also supports maltose and possibly oligosaccharide synthesis from the glucose product. It was concluded that cane amylase is a glucosidase with very general substrate specificity. The action pattern is explained by random encounter of enzyme with substrate, specificity of action at polymer termini, and a nonspecific internal action dependant upon enzyme concentration and time.

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Enzymic Synthesis of Polysaccharides: a Biological type of Polymerization

Hehre¹

1951

Advances in Enzymology - And Related Areas of Molecular Biology

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Products of the Enzymic Degradation of Starch and Glycogen1

Cited by 26 publications

References 56 publications

Physiology of the fungi [by] Virgil Greene Lilly [and] Horace L. Barnett.

Physiology of the fungi [by] Virgil Greene Lilly [and] Horace L. Barnett.

The Action Pattern of Sugarcane-Leaf Amylase

Enzymic Synthesis of Polysaccharides: a Biological type of Polymerization

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