Other Lower Animal

Vitamin A [79-80-1] (6) is stmcturaHy similar to vitamin A [68-26-8] and is also found in fish oils. This compound is important biologically for fish and other lower animals. Interestingly, tadpoles require vitamin A but after metamorphosis require vitamin A (8). 

The major structural polysaccharide in the exoskeletons of arthropods and of other lower animal forms is chitin, a linear P-l,4-linked polymer of N-... 

The core structure of X-glycans is invariably the trimannosyl chitobiose unit, Man3GlcNAc2, which can be a6-fucosylated at the reducing end GlcNAc. In plants, this core fiicosylation is a3 where it occurs, with and without additional / 2-xylosylation at the /3-mannose. In insects, either or both types of core fiicosylation can occur but not /32-xylosylation, whereas in some other lower animals that have been looked at, including mollusks and nematodes, instances of all these core modifications could be found. 

Several protozoa and other lower animals such as the sea anemone Anthopleum elegantissima contain phosphonolipids in their membranes which carry 2-aminoethylphosphonate as a polar group, analogous to ethanolamine phosphate... 

Marine Invertebrate and Other Lower Animal Biosynthetic Products... 

Irradiated small mammals released into the environment had a lower survival rate than laboratory populations, suggesting that the extrapolation from laboratory results may overestimate the radioresistance of free-ranging voles and other small animals because of the general level of stress in the population (Iverson and Turner 1976). The opposite was observed in eastern chipmunks given high sublethal doses of X-rays. Chipmunks had an overall reduction in mobility when they were released... 

CLA has also been identified in the tissue lipids of other nonruminant animals. The CLA concentration in nonruminant animals (chicken and pig) is considerably lower than ruminant animals (Table 1). The exception among nonruminants is turkey (2.51 mg CLA/g fat), which is about five fold higher than chicken or pork. More than 76% of the CLA isomer found in nonruminant tissues is cis-9, trans-11 isomer. 

Other animals, too, have been found not to be entirely dominated by concrete rewards. Hungry monkeys have been observed to prefer exploration tasks to tasks which obtained food and even in lower animals like rats the power of visceral rewards such as food and sexual activity are modified by factors like variety, which are wholly unnecessary to the physical consumption of those rewards (Fisher 1962 Wilson. Kuehn and Beach 1963 Walker and King 1962). 

This phrase is understood as a process which maintains a population or community as an entity (Khailov, 1971). Particular metabolites act as signals , either attracting or repelling other fish, while others have trophic significance. The former have already been given close consideration in a number of books on behaviour and ethology, so need no further comment here. The latter captured the attention of researchers relatively recently. It was found that the uptake of metabolic products is an important factor that cements aquatic ecosystems, from plants to lower animals (protozoans, coelenterates, molluscs and some others). Metabolites that play a trophic role are inorganic... 

The vast majority of mitochondria use oxygen as a terminal acceptor of electrons. Along with aerobically respiring mitochondria, versatile mitochondria exist in which both oxygen and other oxidized compounds, e.g. fumarate and nitrate, serve as electron acceptors. Such sophisticated mitochondria were reported in several ciliates, fungi, and even lower animals (Tielens et al. 2002). The yield of ATP is, however, much lower in the cases of anaerobic respiration, as compared with 32-36 mol per mole of glucose produced by aerobic respiration (Saraste 1999). 

Developments in the chemistry of hormones of insects and other arthropods have shown that the simple picture of a few compounds and a few actions has become less simple. Advances in analytical methods and the increasing number of species studied have thrown up more variations on the simple rules. We are learning more about the interactions between plants and insects, and the conservation of biosynthetic routes between them, and across the phyla. The subject of eicosanoids in insects and lower animals is going to demand further investigation. 

Squalene oxidases enantiospecifically and regiospecifically epoxidize the terminal double bond of squalene 1 to give (31S )-squalene epoxide 258. This, in turn, is the precursor of triterpenes and sterols (e.g., 3) in both plants and animals. Squalene oxidases are found in higher forms of life with the probable exception of insects and terrestrial annelids. They are also present in algae and other lower forms with the possible exception of some bacteria. The enzyme system requires molecular oxygen, NADPH and FAD as well as supernatant protein and phospholipids. There is no evidence for the participation of cytochromes P-450. 

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