Fatty acid metabolism temperature

In summary C. crispus and P. lanosa show similar alterations of fatty acid metabolism in response to Illumination and temperature changes as do higher plants and other algae. The acyl lipids, particularly of C. crispus, also show changes in their metabolism but not always in the same way as has been observed in higher plants. It is unclear from this work... 

Fatty acids are clearly larger in size and show markedly slower diffusion velocity than the small water (or creatine) molecules which have been examined so far by diffusion weighted NMR spectroscopy. However, assessment of diffusion properties of lipids could be a key step for further experimental studies of skeletal muscle lipid metabolism. Diffusion properties of FFA and triglycerides are likely different due to differences in molecular weight. In addition, effects of temperature, chemical surroundings, and the mobility of small lipid droplets in the cytosol may also lead to measurable differences in the diffusion characteristics. 

An interesting observation is tiiat tile larger tiie amount of unsaturated fatty acids in the diet of hibernating animals, prior to hibernation, tiie lower tile body temperature falls during hibernation. The lower tiie temperature, tiie lower is the metabolic rate, which is important in survival from a prolonged period of hibernation. It is suggested that this is caused by an increase in fluidity of membranes but the mechanism is not known. 

Sea animals are rich in soluble dietary fibers, proteins, minerals, vitamins, antioxidants, phytochemicals, and polyunsaturated fatty acids, with low caloric value. Polysaccharides from marine animals have been reported to possess biological activities with potential medicinal values in addition to their current status as a source of dietary fibers and prebiotics. Moreover, they have a lot of dietary fiber, which lowers blood cholesterol, and iodine, which improves metabolism, vascular and cardiac action, body temperature, and perspiration regulation, and are effective in... 

Metabolic processes speed up appreciably under the influence of caffeine. Fatty acids are released into the blood, and a general increase in metabolism is evident as there is increased muscle activity, raised temperature, or both. More calcium is made available through caffeine s action in the muscles for contraction, but this effect is evident only at caffeine doses higher than people commonly use. Gut motility and secretion increase with a release of stomach acid and digestive enzymes. Urination is also stimulated caffeine directly affects the kidneys, cutting into their ability to reabsorb electrolytes and water. For every cup of coffee or two to three cans of caffeinated soft drink consumed, about 5 mg of calcium is lost in the urine. 

Rabinovich and Ripatti (1990) have shown that docosohexaenoic acid has conformational properties which keep its physico-chemical and, possibly, functional characteristics effective over a wide temperature range. This ensures the adaptation of cell membranes to changes of metabolic activity. Fluctuation in locomotory activity is one factor responsible for these changes. From their studies of the sea cucumber, Cucumaria frondatrix, Kostetsky et al. (1992) concluded that polyenoic acids of linolenic affinity did not exhibit a direct relatonship with temperature adaptation. In contrast to this, Zabelinsky et al. (1995) claim that C20 5o>3 (not C22 6a>3) and Cl8 1 are the fatty acids of key importance for temperature adaptation in marine fish. 

Given, the same temperature conditions, the natural mobility rate is the determinant of specific oxygen uptake, energy metabolism, the ratio between protein and lipid used in metabolism, the level of tissue enzyme activity, the rate of self-replenishment of proteins, the energy capacity of tissues, the concentration of erythrocytes and haemoglobin in the blood, the lipid fraction and fatty acid composition of lipids in the liver and other tissues, and the pattern of mobilization in endogenous feeding. 

Farkas, T., Csengeri, I., Majoros, F. and Olah, J. (1980). Metabolism of fatty acids of fish. III. Combined effect of environmental temperature and diet on formation and deposition of fatty acids in the carp. Aquaculture 20,29-40. 

Physically, the membrane may exist in two states the "solid" gel crystalline and the "liquid" fluid crystalline states. For each type of membrane, there is a specific temperature at which one changes into the other. This is the transition temperature (Tc). The Tc is relatively high for membranes containing saturated fatty acids and low for those with unsaturated fatty acids. Thus, bilayers of phosphatidylcholine with two palmitate residues have a Tc = 41°C but that with two oleic acid residues has a Tc = -20°C. The hybrid has a Tc = -5°C. Sphingomyelin bilayer, on the other hand, may have a Tc of close to body temperature. In the gel crystalline state, the hydrophobic tails of phospholipids are ordered, whereas in the fluid crystalline state they are disordered. At body temperature, all eukaryotic membranes appear to be in the liquid crystalline state, and this is caused, in part, by the presence of unsaturated fatty acids and in part by cholesterol. The latter maintains the fatty acid side chains in the disordered state, even below the normal Tc. There is thus no evidence that membranes regulate cellular metabolic activity by changing their physical status from the gel to the fluid state,... 

Cis double bonds produce a kink, or a bend, of about 30 degrees for each double bond into the backbone, and these can flip over to the trans form under high temperatures. Trans double bonds allow the molecule to lie in a straight line however, the human body cannot convert the trans form into nutrients and so prevents the metabolic activities from converting it to the active cis forms. This can lead to a deficiency in essential fatty acids. The more double bonds, and therefore more kinks, the more beneficial it is to human health. By completely changing the physical and chemical properties, the kinks allow essential protein associations to form more easily, thus permitting more saturated fatty acids to disperse and interact with water or blood. 

C. Malignant hyperthermia does not involve central brain control of temperature but is caused by metabolic alterations. Regardless of the source of energy—whether fatty acids or the utilization of ATP to support muscle contraction—the electron transport chain is involved. Uncoupling of oxidation from ADP phosphorylation is caused by uncoupling proteins that dissipate energy as heat. This causes the elevation of body temperature seen in this patient. 

Inaeases in ambient temperature can, by increasing general metabolism, result in an increase in the level of active constituent. Excessively high temperatures can cause loss of volatile materials from leaf surfaces. In the case of the fixed oil from linseed, plants grown in cooler northern climates tend to have a high level of unsaturated fatty acids while those grown in warmer areas tend to be low in unsaturates. 

We can envisage that the distribution of fatty acid residues observed with the phospholipids in biological tissues provides the correct fluidity at a particular environmental temperature to match the required diffusion or rate of metabolic processes required for the tissue. Thus in membranes where metabolic and diffusion processes must be rapid, such as in the mito-... 

---