Metabolism Flashcards
distribution of human daily energy
70% basic organ function
20% physical activity
10% thermoregulation
heterotrophs
derive energy from other organisms (food)
metabolism
body processes that use or produce energy
metabolic rate
the rate at which body energy is used in metabolism
metabolism adjusted to meet ___
specific needs
more body activity = ________
higher overall energy use (metabolic rate)
what is metabolism regulated by
central nervous system and hormones
change in metabolic rate is seen as:
altered O2 consumption, CO2 production, production of H+, heat production
endotherm metabolism
evolved a high rate of metabolism to maintain body temperature
how is metabolic rate measured
O2 consumption and CO2 production (indirectly)
larger vs small animal O2 consumption
larger animals need less oxygen per mass of tissue than small animals
mass specific metabolic rate
mass specific metabolic rate decreases as animal mass increases
whole-animal metabolic rate
metabolic rate increases with mass of animal
large animal body heat maintenance
more efficient than small animals, less surface area to volume ratio to lose heat
endotherms
generates heat internally to maintain a steady body temp
ectotherms
depend on external sources of body heat
homeotherms
maintain a near constant body temp
poikilotherms
do not maintain a steady body temp
thermoregulation
maintaining of internal body temp by generation of excess heat
advantages of ectotherms
less food needed, lower body energy expenditures
disadvantages of ectotherms
need to cope with fluctuating body temps
advantages of endotherms
always an optimal temperature of body
disadvantages of endotherms
need a constant supply of high quality food
what maintains balance of heat loss & gain in endotherms?
negative feedback loop
thyroid hormones
cellular regulators of metabolism in endotherms
