Entropy Flashcards
Ectotherm definition
An organism in which internal physiological sources of heat are of negligible importance in controlling body temperature
Endotherm is
An organism whose body temperature is maintained using the heat released by metabolic processes
What happens when hummmingbirds enter torpor at night
Their body temperature drops close to ambient temperature
Why does the body temperature of ectothermic deep sea fish hardly vary
Live in stable conditions
Turtles are gigantotherms - what does this mean
Can keep a constant body temperature more easily than smaller organisms
Bigger the animal the smaller the SA to V ration so
Get hotter quicker
Are human mammals and birds endothermic
Yes
What is a poikilotherm
Animal whose body temperature varies within its environment
What is a homeotherm
Animal that has a relatively constant body temperature
Is an otter a heometherm
Yes
Is a largemouth bass a poikilotherm
Yes
How much more food does an otter need than a bass
10 times
100 times when it’s close to freezing
What is the metabolic rate of endotherm a compared to ectotherms, independent of body size
10 times more
Metabolic rate is proportional to body size
Bigger the organism the higher the metabolic rate
Explain the second law of thermodynamics
During every transformation some energy is converted to thermal energy and released as heat
This heat warms up the organism and makes the universe more disordered - increasing entropy
At rest how much heat do humans produce each
100W
What does the production and use of ATP generate
Heat which the animal eventually gives off to its surroundings
What do animals use as chemical energy
Food
How is food digested
By enzymatic hydrolysis
What are nutrient molecules absorbed by cells use for
To make ATP
What is the energy form ATP production used for
Biosynthesis
Synthesis of storage material
Production of ganetes
What does biosynthesis doc
Grow and repair cells
How many KJ if energy is related per gram of glucose broken down
15.94
What is the Gibbs free energy of 1 gram of glucose being broken down
-2870 KJ/mol
What % of energy stored in glucose molecule is transferred to ATP
34 - the rest is lost to heat
Cellular respiration equation
C6H12O6 + 6O2 -> 6CO2 + 6H2O
Explain the leaky membrane thing in endotherm a
Less efficient electron transport chains, generating more heat
What happens during oxidative phosphorylation
Electron transport chains covert the chemical energy to ATP via chemiosmosis
How do normal mitochondria produce ATP
Electrical current of protons across their membrane - need an intact membrane to act as an insulator
What is non shivering themogenesis
When certain hormones cause cause mitochondria to increase their metabolic activity and produce heat instead of ATP
This occurs in brown adipose tissue when the mitochondria have protein pores allowing protons to leak out
Brown adipose tissue is
Brown fat
What does the red muscle in tuna and lamnid sharks have a similar function to
Brown fat
How much energy does the hydrolysis of ATP produce per mol
30.5
How much energy from the the hydrolysis of ATP fuels cellular processes
40%
How many grams of atp is in humans
250g
What does muscular activity generate a lot of as a by product
Heat
Why is aerobic capacity an advantage of endothermy
Lizards are great sprinters but build up lactic acid quickly
Mammals have ten times more aerobic capacity
Selection for maximal metabolic rate dragged up basal metabolic rate because they are intrinsically linked
Selection for stamina leads to hotter bodies
Parental care is the driver for
Increased stamina
What are the 4 advantages of endothermy
Aerobic capacity
Parental care
Permian extinctions
Vegetarianism
Explain Permian extinctions
High CO2 low o2 calls volcanic winters and temperature fluctuations
Selected for endothermy
How long did lystrosaurs dominate the terrestrial environment
50 million years in the Triassic
What do the respiratory turbinates of lystrosaurs indicate
Endothermy
What did klaassen and biker suggest about endothermy
It evolved in herbivores as a way of burning off excess carbon when feeding on a nitrogen poor diet
Many archosaurs and lystrosaurs were what
Herbivores
How much of human body mass is brain
2%
How much energy does the human Brian consume
20%
How much energy does the baby/foetus human brain consume
Up to 60%
What did the evolution of a large brain in mammals and birds coincide with
Development of endothermy
Endothermy requires lots of what
Energy
Most heat produced is a what of metabolism
By product
What are the advantages of endothermy
Stamina
Respiratory efficiency
Burn off excess carbon
What did endothermy permit
Evolution of a large brain
