. Biology and human life. Biology. THE AIR i6i which also takes place in water. Protoplasm oxidation probably depends upon the action of special ferments, or enzyms (see section 105). (i) It involves (a) material that can act as fuel, and ib) oxygen. (2) It results in the formation (a) of carbon dioxid (since all the fuel contains carbon), (b) of water (oxid of hydrogen, since all the fuel contains hydrogen), and (c) of other oxids, depending upon the character of the fuel. The familiar fires give off heat and light. Oxidation in protoplasm may also re- sult in other forms of energy. Some of t
. Biology and human life. Biology. THE AIR i6i which also takes place in water. Protoplasm oxidation probably depends upon the action of special ferments, or enzyms (see section 105). (i) It involves (a) material that can act as fuel, and ib) oxygen. (2) It results in the formation (a) of carbon dioxid (since all the fuel contains carbon), (b) of water (oxid of hydrogen, since all the fuel contains hydrogen), and (c) of other oxids, depending upon the character of the fuel. The familiar fires give off heat and light. Oxidation in protoplasm may also re- sult in other forms of energy. Some of these are motion (as in muscles), electricity, and the peculiar processes that are confined (so far as we know) to nerve and brain cells, such as thinking, wish- ing, suffering, enjoying. 135. Cell respiration. In an engine the oxidation takes place in the fire box or the cylinder. In a living plant or animal oxidation takes place in every single cell. In plants and animals that consist of very many cells the innermost cells are too far from the surface to get their oxygen directly from the surrounding air or water in this manner. In such cases the air either diffuses through special spaces (in plants) or special tubes (in insects: see Fig. 7), or it travels in a solution (blood) that reaches all parts of the body. In every case, then, the protoplasm of the individual cell (i) gets. Fig. 83. The human lungs The arrows show the course of air from the outside, m, mouth; «, nostrils: p. pharynx: /, laryrLx; t, trachea; b, bronchi. The right lung is shown cut open; the bronchi branch again and again, the last tubules ending in delicate expansions, a, the air cells, or sacs; epi, the epiglottis, which closes over the air pipe when food passes from the pharynx to the esophagus, e. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the o
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Keywords: ., bookcentury1900, bookdecade1920, bookpublishe, booksubjectbiology
