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Basal metabolic rate

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Basal metabolic rate ( BMR ) is the rate of energy expenditure per unit time by endothermic animals at rest. [1] It is reported in energy units per unit time ranging from watt (joule/second) to ml O 2 /min or joule per hour per kg body mass J/(h·kg). Proper measurement requires a strict set of criteria be met. These criteria include being in a physically and psychologically undisturbed state, in a thermally neutral environment, while in the post-absorptive state (i.e., not actively digesting food). [1] In bradymetabolic animals, such as fish and reptiles, the equivalent term standard metabolic rate ( SMR ) is used. It follows the same criteria as BMR, but requires the documentation of the temperature at which the metabolic rate was measured. This makes BMR a variant of standard metabolic rate measurement that excludes the temperature data, a practice that has led to problems in defining "standard" rates of metabolism for many mammals. [1] Metabolism comprises the proc...

Nutrient sensing

Nutrient sensing is a cell's ability to recognize and respond to fuel substrates such as glucose. Each type of fuel used by the cell requires an alternate pathway of utilization and accessory molecules. In order to conserve resources a cell will only produce molecules that it needs at the time. The level and type of fuel that is available to a cell will determine the type of enzymes it needs to express from its genome for utilization. Receptors on the cell membrane's surface designed to be activated in the presence of specific fuel molecules communicate to the cell nucleus via a means of cascading interactions. In this way the cell is aware of the available nutrients and is able to produce only the molecules specific to that nutrient type. Contents 1 Nutrient Sensing in Mammalian Cells 2 Nutrient Sensing and Epigenetics 3 Regulation of Tissue Growth Through Nutrient Sensing 4 Nutrient Sensing in Plants 5 Types of Nutrients in Plants 5.1 Nitrog...