Protoplasm properties

Protoplasm, Properties, with Special Reference to Influence of Enzymic Reactions (Sedriz). VII 35... 

Many competent investigators regard viscosity as one of the most significant of protoplasmic properties. On it, they say, do such basic activities as amoeboid movement, cyclosis, and metabolism depend but this is only indirectly true. It is contractility and not viscosity on which protoplasmic movement primarily depends the two properties are independent variables. Viscosity plays its ]iart in protoplasmic movement, but it is not a cause. If the force responsible remains constant, the rate of movement will be inversely proportional to the viscosity of the protoplasm but, if the motive force varies, the rate of flow will vary in direct proportion to it, and the viscosity need not change at all. The situation is similar in the case of metabolism viscosity plays a secondary part. Lh6risson (44) has pointed out that metabolic rate is inversely proportional to viscosity. He bases this conclusion on the fact that the rate of chemical reactions is dependent upon diffusion and rate of diffusion is proportional to viscosity. 

Plants have a specific property, which is excitability [1-3]. This property is used by cells, tissues, and organs to change their internal condition and external reactions under the action of various environmental factors, referred to as irritants. The high sensitivity of protoplasm and all cell organelles to any natural and electrochemical effects is the basis for... 

By the early years of this century the cell was generally recognized as the smallest unit capable of independent life. Gowland Hopkins in 1913 first clearly formulated ideas which would be the death of protoplasm. Life is the expression of a particular dynamic equilibrium which obtains in polyphasic systems. .. life is a property of the cell as a whole. ... 

Most of the early work on membranes was based on experiments with erythrocytes. These cells were first described by Swammerdam in 1658 with a more detailed account being given by van Leeuwenhoek (1673). The existence of a cell (plasma) membrane with properties distinct from those of protoplasm followed from the work of Hamburger (1898) who showed that when placed in an isotonic solution of sodium chloride, erythrocytes behaved as osmometers with a semipermeable membrane. Hemolysis became a convenient indication of the penetration of solutes and water into the cell. From 1900 until the early 1960s studies on cell membranes fell into two main categories increasingly sophisticated kinetic analyses of solute translocation, and rather less satisfactory examinations of membrane composition and organization. 

It is difficult to explain why toxic hydrocarbons can be made selective to carrots by the addition of a nontoxic oil but not by the addition of water. Green (7) found some correlation between the toxicity of oils and their ability to emulsify. It is commonly found that high aromatic oils are easier to emulsify than are oils with low aromatic content. It is possible that some action between the aromatic hydrocarbons and the emulsifying agent results in increased toxicity. There is some evidence that the permeability of the protoplasmic membrane is the key to carrot resistance. If this is true, the presence of the emul er or the physical properties of the emulsion might increase the cell penetration of the hydrocarbons. Work is being continued along these lines and on the fundamental reasons for differential plant resistance to oils. 

The peculiar properties which distinguish protoplasm from nonliving matter are as follows ... 

Reproduction.—Protoplasm also shows a very remarkable ability to increase and to give ofi detached portions which retain the infinitely complex peculiarities and properties of the original. The process, moreover, may be continued indefinitely. 

Ten pages have been added to Chapter V on Cytology. Under Protoplasm and its Properties, six pages have been written on the subject of Irritability and Irritable Reactions. Under Non-Pro toplasmic Cell Contents several additional commercial starches are discussed and two original plates on starch grains added. Additional cuts on Collenchyma, Stone Cells, Sclerenchyma Fibers, Trichomes and Fibrovascular Bundles have been inserted in Chapter VI. 

In the process of reproduction the yeast cells need nitrogenous substances for new cells, and therefore it gives off a proteolytic enzyme, which has the property of breaking up the complex proteins into tiie amino acids and amides, which are then synthesized into the protoplasmic structure of the yeast cells. 

Matter exists not only in the organic forms of solids, liquids and gases and in the disintegrated forms of electrons and protons, it exists also as the complex molecules known as protoplasm, which for some reason or other has shewn itself to be the vehicle of life. Some forms of matter are endowed with or animated by life. This property of animation is a great mystery we do not know what Life is, we only see what it can do. We perceive that it can enter into relation with matter, that it has a character and identity of its own, and that it builds up matter to correspond with or to represent identity. Life can take a variety of forms, and every form is characterized by a certain shape the life of an oak is transmitted to an oak, the life of an elm to an elm. "To every seed his own body." One form of life takes the shape of a bud, another of a fish, another of a quadruped. The varieties of life are innumerable, and are studied in the great science of biology. 

The importance of albuminoids , now known as proteins, in animal nutrition was recognized by the first half of the last century through the work of F. Magendie. The analytical studies of G. Mulders in 1840 on substances such as egg albumin, milk casein and blood fibrin led to the formulation of a theory on the energy rich character of protoplasmic proteins. In 1881 Oscar Loew put forward a theory that, for the dynamic properties of protoplasmic proteins, the aldehyde group should be responsible and, according to the chemical knowledge of the time, P.W. Latham wrote in 1897 that albumin is... 

I. Inoue, Y. Ishima, H. Horie, and T. Takenaka, Properties of an Excitable Membrane Produced on the Surface of a Protoplasmic Drop in Nitella, Proc. Jpn. Acad. 47, 549-553... 

As already mentioned, phenol derivatives are membrane-active microbicides. They adsorptively coat the surface of the microbe cell then, at a higher concentration, they are dissolved more or less rapidly and well by lipoids depending on their chemico-physical properties (see above). They attack the cell wall and penetrate into the cell. There are reactions with the protoplasm and the cellular protein enzymes are also inhibited as a result the oxidoreductases and the enzymes of carbohydrate and protein metabolism react particulary sensitively. Whether the phenol derivatives act microbistatically or microbicidally is purely a question of the application concentration. At low concentrations in ambient medium, there is only reversible adsorption of the phenolic active substance at the cytoplasmic membrane and the related inhibiting effect. As stated above the cell wall is only penetrated and destroyed and the microbe cell killed at higher concentrations. 

Chambers R Jr. Microdissection studies on the physical properties of protoplasm. Lancet-Clinic, Cincinnati 113 363-365, 1915. Chambers was rebutting the opinion of FS Hammet (The source of hydrochloric acid found in the stomach. Anat Rec 9 21-25, 1915) that FitzGerald, and not Harvey and Bensley, had been right. 

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