General structure and function

General class Number of carbon atoms Formula Trivial name Aldose Ketose 

All carbohydrates can exist in either of these two forms and the prefix of D or L only refers to the configuration around the highest numbered asymmetric carbon atom. Enantiomers have the same name (e.g. D-glucose and L-glucose) and are chemically similar compounds but have different optical properties. The majority of naturally occurring monosaccharides, whether they be aldoses or ketoses, are of the D configuration. 

Each time the number of carbon atoms is increased by one (with the addition of a CHOH group) a new carbohydrate is produced which has a chemically distinct form and a completely different name. Because this group 

HCOH HOCH HCOH 1 HOCH 1 HCOH 1 HOCH 1 I HCOH i 1 HOCH i 

HCOH HCOH 1 HOCH HOCH HCOH 1 1 HCOH 1 1 HOCH i 1 HOCH 1 

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Some General Structural and Functional Properties of Bacterial Cell Envelopes... 

We have described a general relationship between structure and function for the a/p-barrel structures. They all have the active site at the same position with respect to their common structure in spite of having different functions as well as different amino acid sequences. We can now ask if similar relationships also occur for the open a/p-sheet structures in spite of their much greater variation in structure. Can the position of the active sites be predicted from the structures of many open-sheet a/p proteins ... 

The neurotransmitter acetylcholine (ACh) exerts its diverse pharmacological actions via binding to and subsequent activation of two general classes of cell surface receptors, the nicotinic and the mAChRs. These two classes of ACh receptors have distinct structural and functional properties. The nicotinic receptors,... 

Basic Properties of Sulfosuccinate Diesters It is very difficult to establish general structure-function relationships for the sulfosuccinate diesters, although they are very similar in structure and functionalities. Looking at the variety known for these compounds, only different hydrocarbon chains—branched, linear, or cyclic—are in use. In the following chapter, basic properties of these compounds depending on the substituents used are described. 

The following sections of this chapter will consider some general and comparative aspects of receptor structure and function. More detailed material on these topics may be found in the relevant chapters on individual neurotransmitters. 

An analogous role has been played by other scientists in strengthening the ties between quantum chemistry of type I (and type II) with the area corresponding to biochemistry (or complex molecular systems in general), a task made more difficult by the explosive growth of structural and functional information about biomolecular systems. It is worth to remark here that such a fruitful use of quantum chemical concepts in biology has requested the extension of the methods to approaches different from quantum molecular theory in the strict sense introduced before. We shall comeA back to this remark later. 

An appropriate starting point for any discussion of drug transport in the gastrointestinal (GI) tract at the cellular level requires some introductory remarks on the structure and function of GI tissue. As a class of tissue, epithelia demarcate body entry points (skin, eye, respiratory, urinary, and GI organ systems), predisposing a general barrier function with respect to solute entry and translocation. In addi-... 

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