Form and function

Long chains of water-insoluble lipids are constructed from building blocks called fatty acids, which are also stowed away as a source of fuel in fat cells. The chemical bonds linking fatty acid units together in glycolipids and phospholipids determine how rigid or floppy the lipid chains will turn 

Anatomy is to physiology as geography is to history it describes the theater of events. 

Turbulence is enhanced by a passage with nonuniform cross section and by twists and turns and protrusions. Notice that the nasal cavity has a large surface area, it is of variable cross section, and the path of the air makes a large turn before entering the throat. The large cross-sectional area means that the air velocity slows from its value at the nostrils, increasing the residence time of the air in the cavity and giving it the time to be heated and humidified. 

The location of the olfactory receptors is in the place (at the top of the cavity) where it is most likely that incoming chemical molecules will strike the surface. When chemical molecules do contact receptors, they must fit together before a nervous signal can be generated. This requires that the receptor must have a shape complementary to the shape of the chemical in order that the two join together. Each different class of chemicals generally has a different set of receptors sensitive to that chemical class. The form of the nasal passage and the form of the receptors are both determined by their functions. 

Among other things, the fingers must obtain touch information. Thus, the touch receptors are located close to the skin surface. These receptors are not sensitive to light, as are the receptors in the retina of the eye, but do have some sensitivity to temperature. 

Plants have skeletons, too, but plants are not usually mobile, so they have distributed skeletons. The cell walls of plants are made of rigid cellulose, thus giving plants the ability to withstand forces that would ordinarily drive animals to move to shelter. 

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Amalgam restorations are prepared by mixing a powdered alloy with mercury to form a plastic moldable mass that is packed or condensed iato the prepared cavity. The cavity is designed to provide mechanical retention, maximum marginal mass, support to absorb the functional stresses transmitted through the restoration, and maximum protection to the remaining tooth stmcture. The restoration reestabUshes the normal tooth anatomical form and function. 

Plant cell mitochondria resemble the mitochondria of other eukaryotes in form and function. 

Torres GE, Amara SG (2007) Glutamate and monoamine transporters new visions of form and function Curr Opin Neurobiol 17 304-312... 

Kuhns MS, Davis MM, Garcia KC (2006) Deconstructing the form and function of the TCR/CD3 complex. Immunity 24 133-139... 

Quaternary ammonium compounds are cationic surfactants that bind well to anionic surfaces like the protein in hair. The ammonium end sticks to the hair, leaving the long fatty end of the molecule to act as a lubricant. They are slightly conductive, so they reduce the buildup of static electricity. Quats, as they are sometimes called, include compounds like stearalkonium chloride, disteardimonium chloride, quaternium-5, or quaternium-18, polyquaternium-10 and they are all similar in form and function to cetrimonium chloride. These compounds are also widely used as fabric softeners, for all of the same reasons they make good hair conditioners. They are also used to thicken the shampoo. 

Robichaux, R.H., Holsinger, K.E. Morse, S.R. (1986). Turgor maintenance in Hawaiian Dubautia species the role of variation in tissue osmotic and elastic properties. In The Economy of Plant Form and Function, ed. T. Givnish, pp. 353-80. Cambridge Cambridge University Press. 

Plant canopies their growth, form and function. Edited by G. Russell, B. Marshall and P.G. Jarvis... 

Fent, K., Woodin, B.R., and Stegeman, J.J. (1998). Effects of triphenyl tin and other organotins on hepatic monooxygenase system in fish. In D.R. Livingstone and J.J. Stegeman (Eds.) Forms and Functions of Cytochrome P450, 277-288. 

J. M. Lynch, The rhizosphere—form and function, Applied Soil Ecology / 193 (1984). 

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