Animals endothermic

An endothermic animal generates its own body temperature, while an ectothermic animal does not. In general, endothermic animals have constant body temperatures that are typically greater than that of the surrounding environment, while ectothermic animals have variable temperatures. Ectotherms rely on behavioral temperature regulation—a snake will move from sun to shade until it finds a suitable microclimate that is close to its optimal body temperature. When exposed to direct sunlight, an ectotherm can increase its body temperature as much as 1°C (32.8°F) per minute. 

Endothermic animals can achieve and sustain levels of activity even when temperatures plummet or vary widely. This can be a huge advantage over ectothermy, especially m northern latitudes, at night, or during the winter. In colder climates, an ectothermic predator such as a snake will tend to be more sluggish and less successful than an endothermic predator. There are no reptiles or insects in the polar regions. 

Birds and mammals are endothermic vertebrates. Not coincidentally, they are the only vertebrates with unique external body coverings—feathers and hair, respectively. For both groups, these body coverings evolved as an adaptation to reduce heat loss. A bird s feathers were originally adaptive because they helped keep the animal warm, not because they helped it to fly. 

In addition to these challenging physical constraints, the demands for food that an endothermic homeotherm faces are substantially greater than those for an ectotherm of the same body mass. At the same body temperature, on a unit mass basis, similar-sized endotherms and ectotherms differ in oxygen consumption on average by at least four- to fivefold (see Brand et al., 1991). It is obvious that many ectother-mic species may not have access to enough food, at all times, to make it possible, even in principle, for them to become endothermic homeotherms. An ecosystem in which all animals are endothermic homeotherms is probably impossible. 

In light of the constraints that animals face in developing endothermic homeothermy, it may... 

Mammals and birds are the only groups of animals having a capacity for effective systemic endothermic homeothermy. The origin of this important capacity has long intrigued physiol-... 

Endothermic homeotherms are characterized by high mass-specific rates of oxygen consumption relative to similar-sized ectotherms. This difference can be shown by examining the allometric scaling relationship between rate of oxygen consumption (M) and body mass (IF). For ectothermic and endothermic animals, whole animal oxygen consumption rate is proportional to total body mass raised to approximately the 0.75 power ... 

Use SpertanView to obtain enei ea for the molecule in the ftdiowiiv reocUon. and use these energies to animate A/T for the reaction. Is the reaaion exothermic or endothermic ... 

Endotherm— An animal that uses its metabolism as a primary source of body heat and uses physiological mechanisms to hold its body temperature nearly constant. 

Animals that are described as warm blooded, or endothermic, maintain a constant internal temperature, even when exposed to extreme temperatures in their environment. In mammals, this internal temperature is about 97°F (36°Q, while in birds, it is warmer, around 108°F (42°Q. 

Bihari-Varga (223) used DSC for the assay of glycosaminoglycans (GAG) and for the characterization of the stability of crosslinked proteins in intact human and animal tissues. By this method, age-related and pathological changes and repair reactions could be studied in various connective and vascular tissues. A typical DSC curve of human serum low-density lipoprotein (LDL) and of an aortic-GAG-LDL complex is given in Figure 7.3. A reversible endothermic transition took place in the LDL molecule at 33°C. Choiesteryl esters within the LDL core existed as an isotropic solution above this temperature and in the form of the smectic liquid crystals below it. When LDL was converted to GAG-LDL complexes, the transition temperature was increased to 40°C. 

Interactive Figure To see an animation of heat flow in endothermic and exothermic reactions, visit giencoe.com. 

The most obvious features when scanning a solution of proteins are the denaturation peaks. For instance, if bovine serum albumin (BSA) with and without fatty acids in aqueous solution is heated, and not subjected to too high a temperature, nearly reversible endothermic peaks are obtained [77]. This is the case for many globular proteins of animal and plant origin, such as lactoglobulin and the wheat proteins gliadin and glutenin [78,79]. 

Sometimes there is confusion due to different use of terms. Thermodynamics calls a process exothermic when heat is given off by the system and endothermic when it consumes heat. In biology, warm-blooded (homeothermic) animals like mammals and birds that produce heat to keep their body temperature constant are called endotherms and their behaviour endothermic, in contrast to the thermodynamical direction. Their counterparts with changing body temperatures are ecto-therms (not exotherms) or cold-blooded poikilothermic) animals. Nevertheless, all of them produce heat as a by-product of their metabolism so that they can be monitored by (exothermic) calorimetry. 

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