Taste explanations

Flavor has been defined as a memory and an experience (1). These definitions have always included as part of the explanation at least two phenomena, ie, taste and smell (2). It is suggested that in defining flavor too much emphasis is put on the olfactory (smell) and gustatory (taste) aspects (3), and that vision, hearing, and tactile senses also contribute to the total flavor impression. Flavor is viewed as a division between physical sense, eg, appearance, texture, and consistency, and chemical sense, ie, smell, taste, and feeling (4). The Society of Flavor Chemists, Inc, defines flavor as "the sum total of those characteristics of any material taken in the mouth, perceived principally by the senses of taste and smell and also the general senses of pain and tactile receptors in the mouth, as perceived by the brain" (5). 

This is the characteristic pattern of an explanation. It begins with a Why question that asks about a process that is not well understood. An answer is framed in terms of a process that is well understood. In our example, the origin, of gas pressure in the balloon is the process we wish to clarify. It is difficult even to sense the presence of a gas. The air around us usually cannot be seen, tasted, nor smelled (take away smog) it cannot be heard or felt if there is no wind. So we attempt to explain the properties of a gas in terms of the behavior of billiard balls. These objects are readily seen and felt their behavior has been thoroughly studied and is well understood. 

There is little doubt that Shallenberger s AH,B hypothesis is the most plausible concept in the explanation of the initial stimulation of the sweet-taste receptor. However, it was unfortunate that the evidence was accrued largely with the aid of reducing sugars, which, in solution, equilibrate between many isomers, so that it is not possible to relate total gustatory response to any one particular stereochemical structure It is also not... 

Taste-modality recognition is a function of the cells of the taste buds. Perception of the sensation is a result of complex processes in the brain. The biological events that are discussed are those that occur, or are suggested as occurring, in taste-receptor cells, beginning at the instant when the taste-stimulus molecule interacts with the cell, until the membrane of the receptor cell is polarized. These are peripheral events. However, our knowledge of the peripheral mechanisms in taste perception is not sufficiently complete to provide a detailed, biophysical explanation of this phenomenon. Nevertheless, several stages in this explanation have been hypothesized, and some are demonstrable. 

We can use the following MATLAB statements to do time response simulations (explanations are in MATLAB Session 5). Better yet, save them in an M-file. The plotting can be handled differently to suit your personal taste. (Of course, you can use Simulink instead.)... 

Whatever the mechanistic explanation for this remarkable result, we hope that we have given the reader a taste of the fruits of considering both the fields of enzyme mechanism and organometallic chemistry. We are exploring the acceleration of other reactions using bifunctional catalysts, and these results will be described in due course. 

Reactions are taking place around you all the time. It is important tto be aware of your surroundings and understand how humans interact with these surroundings. Your five senses allow you to observe the world in which you live. In the lab, you only use four senses to make observations. Nothing is ever tasted in the lab. Sometimes tools can extend your senses. When you describe the color, odor, or texture of an object, you are making a qualitative observation. Quantitative observations involve measured quantities, such as 15 g or 2.5 L. It is important not to confuse observations and interpretations in the lab. Observations are made using your senses interpretations are proposed explanations that are based on observations. In this lab, you will be making both qualitative and quantitative observations. 

It was with the sweet taste of enantiomorphs that we encountered the strongest criticism to our explanation of why sugars vary in their sweetness and also as to the identification of the saporous unit as an AH,B system in all sweet compounds. 

Biochemistry has pushed Darwin s theory to the limit. It has done so by opening the ultimate black box, the cell, thereby making possible our understanding of how life works. It is the astonishing complexity of subcellular organic structures that has forced the question, How could all this have evolved To feel the brunt of the question—and to get a taste of what s in store for us—let s look at an example of a biochemical system. An explanation for the origin of a function must keep pace with contemporary science. Let s see how science s explanation... 

Recently, Ghiaroni et al. (2005) opened the possibility that gambierol could be acting as a voltagegated potassium blocker. They used the patch-clamp technique in order to check the gambierol effect on mouse taste cells. Alteration of the activity of those excitable cells could be an explanation for the... 

Interestingly, the human TAS1R2/TAS1R3, but not its mouse counterpart, are sensitive to the sweet proteins monellin, thaumatin, and brazzein, and to the artificial sweeteners neo-tame, cyclamate, and aspartame (9-11). This difference provides a molecular explanation for the previous observation that these compounds are sweet for humans but not attractive to rodents (9). The species difference also applies to the inhibitor lactisole that blocks the sweet taste in humans but not in rats, and only inhibits the response of human TAS1R2/TAS1R3 to sweet stimuli (9). 

It s better to he hitter. Some nontoxic plants taste very bitter to us. Suggest one or more explanations. 

It is purely a matter of taste whether one should first study chemical equilibrium from the empirical point of view, and then study thermodynamics to provide the fundamental explanation of equilibrium, or learn thermodynamics first as essential background for the study of equilibrium. We have written this textbook to allow either approach. If your instructor prefers to cover thermodynamics before equilibrium, you should read Chapters 12, 13, and 14 straight through in the order written. If your instructor prefers to cover equilibrium from the empirical point of view before studying thermodynamics, you should skip now to Chapter 14 and omit those sections of Chapter 14 (clearly marked) that require background in thermodynamics. You should come back and read those sections later after you have studied Chapters 12 and 13. 

Frank ME, Blizard DA (1999) Chorda tympani responses in two inbred strains of mice with different taste preferences. Physiol Behav 67 287-297 Fuller JL (1974) single-locus control of saccharin preference in mice. J Heredity 65 33-36 Galindo-Cuspinera V, Winnig M, Bufe B, Meyerhof W, Breslin PA (2006) A TAS1R receptor-based explanation of sweet water-taste . Nature 441 354-357 Glaser D, Tinti JM, Nofre C (1995) Evolution of the sweetness receptor in primates. I. Why does alitame taste sweet in all prosimians and simians, and aspartame only in Old World simians Chem Senses 20 573-584... 

It is perplexing to realize that, in essence, the phenomena we found in rats is retraceable in humans. Let us take, as an example, one of the most sophisticated acquired drives in humans the alliance by love, based essentially on the innate sexual drive. Human love as an acquired drive is an extremely complicated, unfathomable set of sentimental ties that are continuously reinforced by sexual relations, but within the alliance of living together (e.g., marriage), love survives the age-related extinction of the sexual drive. It is a common experience that there is no explanation for tastes in the choice of a partner. The tie is based on the acquired drive induced lifelong fixation of an almost unlimited number of chains of ICRs that can be ecphorized any time. Nevertheless, in this case, the sea of almost irreversibly fixed engrams are interwoven with the sexual drive in a complicated manner. 

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