BIOL 005B Lecture Notes - Lecture 11: Basal Metabolic Rate, Cellular Respiration, Ectotherm
BIOL 005B Lecture 11: Animal Energetics- The Cost of Living
●Energy requirements are related to animal size, activity, and environment
○Bioenergetics is the overall flow and transformation of energy in an animal
○It determines how much food an animal needs and is related to an animal’s size,
activity, and environment
●Energy Allocation and Use
○Animals harvest chemical energy from food (heterotrophy)
■Energy-containing molecules from food are usually used to make ATP,
which powers cellular work
■Energy typically may be stored as fat or glycogen
○Energy Budget:
■Energy Total = Maintenance + Biosynthesis + Activity
●After the needs of staying alive are met (maintenance), remaining
food molecules can be used for activity or for biosynthesis
●Biosynthesis includes body growth and repair, synthesis of storage
material such as fat, and production of gametes
○The amount of energy used by an animal in a given period of time is accounted
for by cellular respiration
○Byproducts of Cellular Respiration
■Two byproducts of cellular respiration that are often measured are:
●The heat lost in cellular processes (such as glycolysis)
●The gases used in cellular respiration
○Oxygen and Carbon Dioxide can be easily measured
■C6H12O6 + 6O2 → 6CO2 + 6H2O + 36 ATP + HEAT
○Quantifying Energy Use
■Metabolic rate is the amount of energy an animal uses in a unit of time
(energy use/time)
■One way to measure it is to determine the amount of oxygen consumed or
carbon dioxide produced (ml/time)
●Minimum Metabolic Rate and Thermoregulation
○Basal metabolic rate (BMR) is the metabolic rate of an endotherm at rest at a
“comfortable” temperature (maintenance)
○Standard metabolic rate (SMR) is the metabolic rate of an ectotherm at rest at a
specific temperature
○Both rates assume a non-growing, fasting, and non-stressed animal
○Ectotherms have much lower metabolic rates than endotherms of a comparable
size
●Influences on Metabolic Rate
○Metabolic rates are affected by many factors besides whether an animal is an
endotherm or ectotherm or the external environmental temperature
■Two of these factors are size and activity
●Size and Metabolic Rate
○Large animals eat much more in a day, and expend more total energy, than small
animals
Document Summary
Biol 005b lecture 11: animal energetics- the cost of living. Energy requirements are related to animal size, activity, and environment. Bioenergetics is the overall flow and transformation of energy in an animal. It determines how much food an animal needs and is related to an animal"s size, activity, and environment. Animals harvest chemical energy from food (heterotrophy) Energy-containing molecules from food are usually used to make atp, which powers cellular work. Energy typically may be stored as fat or glycogen. Energy total = maintenance + biosynthesis + activity. After the needs of staying alive are met ( maintenance ), remaining. Biosynthesis includes body growth and repair, synthesis of storage food molecules can be used for activity or for biosynthesis material such as fat, and production of gametes. The amount of energy used by an animal in a given period of time is accounted for by cellular respiration. Two byproducts of cellular respiration that are often measured are:
