bio finals Flashcards
difference in requirements of energy of between ectotherms and endotherms
endotherms require less energy than endotherms
Do organisms have similar enery demands?
Yes
Do organisms spend different amounts of energy to meet each demand?
Yes
does surface area scale with mass like it does in a geometric shape?
absolutely
how do large organisms increase surface area?
they have highl branced circulatory, respiratory, ad digestive systems. humans need 25x the skin surface area
how does the size or mass affect the energy expenditure of organisms?
it influences the way they move, how often and what they eat
how much energy does a large animal require?
it requires a higher absolute energy but less energy per gram
relationship between how long the food stays in the digestive tract and food
how long food remains in the digestive tract is a phenotypic trait that responds to selective pressures in the environment. the longer it takes to digest food, the longer the retention time. ex. protein is easier to digest while carbohydrate and fats stays long in the digestive tract because it is harder to digest.
relationship between length, area and volume
volume is proportional to the length cube nad surface are is proportional to the length squared
relationship between the size of an organism and food
large organisms need more food than small organisms which means that large organisms will have a larger Ein (energy in) value per unit time.
the realtionship between air intake, the volume of blood pumped in each heartbeat and the size
large organisms take in more air with each breath and pump a greater volume of blood in each heartbeat. they have a lower breathing and heart rate than small organisms
the relationship between how often an organism eats and their size
larger organisms can eat more food at a given time than small animals. they also eat less often than small organisms relative to their body size
the surface area of an organism
membrane/skin
the volume of an organism
mass
What are the energy demands of an organism?
Maintenance, growth, activity, reproduction
what do the energy budget depends on?
it depends on size, activity and environment
what id the definition of scaling?
the study of the effect of size/mass on anatomy/physiology
what is a measure of evolutionary fitness?
it is the total amount and rate at which they obtain energy from food
what is allometry?
it is the relation between the size of an organism and aspects of its physiology, morphology, and life history. it also means that it is the scale used when the aspect of biology do not vary proportionally to size
what is Eexcretion?
Eexcretion is the energy released by the body through urine, feces, shedding, heat, etc.
what is isometry?
it means that both dimensions remain proportional. the b value is close to one and when converting it to mass specific, it is zero
what is negative allometry or hypoallometry?
it is when one dimension increases, the other dimension decreases to a lesser proportion. the slope (b) should be less than one
what is positive allometry or hyperallometry?
it is when one dimension increases, the other dimension increases at a greater proportion . the slope(b) should be greater than one.
where do organism exchange matter and generate energy?
across the membranes which is their surface area
what is retention time?
it is the time taken by the food to pass through digestive tract
why do organism need to obtain resources and excrete waste?
to support their mass which is their volume
why do organisms need energy?
organisms need energy to survive and reproduce
why do we use log transformations?
log transformation is sed for data normalization(making the data more regular) and it makes the power function linear
why is animal line higher? (greater intercept)
appendages (projection)
why is it an advantage for large organisms to have a small surface area to volume ratio?
because of easy heat retention. heat is produced by the entire volume and lost through surface area
whyis it a disadvantage for large organisms to have a small surface area to volume ratio?
because the nutrient exchange and energy generation will not be as sufficient
how does energy excretion work?
- food gets broken down (chewing, enzymes, etc.). this takes a lot of energy and represents a net loss od energy. the harder the food to digest, the more energy required
- nutrients are absorbed which leads to a gain of energy
- when most energy is absorbed, the digestion rate decreases
- all possible energy is extracted leaving undigestible “dregs” for excretion
what is the relationship between high quality food, energy and digestion?
high quality food (ex. meat) are easy to digest, less energy loss, greater rate, plateaus sooner, and higher plateau.
what is the relationship between low quality food, energy and digestion?
low quality food (ex. plant) are hard to digest, more energy loss, lesser rate, plateaus later, and lower plateau.
where is the optimal rate and optinal retention time of low quality food?
the optimal rate is at inflection point and optimal retention time is tangent of line drawn from origin
describe energy flow
energy is being recycled and not lost to environment
what is metabolic rate?
-metabolic rate is the rate of energy consumption.
-rate at which it converts chemical energy to heat and external work
-it is measured in calories or joules.
-it is the calories per unit time
what is resting metabolic rate (RMR)?
it is the energy expenditure at rest but riutine activities/day
what is basal metabolic rate (BMR)?
it is the metabolism at complete rest. lowest possible
what is standard metabolic rate (SMR)?
it is the metabolic rate measured at a specified temperature (ectotherms)
what is field metabolic rate (FMR)?
it is the metabolic rate measured in wild animals
which organisms does BMR applies to?
it applies to endotherms
which organisms does SMR applies to?
it applies to ectotherms
when does the BMR and the SMR of an organism applies?
it is the animal’s metabolic rate while it is in its thermoneutral zone, fasting, and resting
when is the SMR specific?
it is specific for the prevailing body temperature
what is direct calorimetry?
direct calorimetry measures the rate at which heat leaves an animal’s body
what is direct calorimetry?
direct calorimetry measures the rate at which heat leaves an animal’s body. it is expensive and cumbersome (complicated, unmanageable)
what is indirect calorimetry?
it is the measure of oxygen consumed or carbon dioxide produced.it is cheaper and easier.
what are the two methods of indirect calorimetry?
respirometry and the material-balance method
what is respirometry?
it is the measuring of an animal’s rate of respiratory gas exchange with its environment.
what is the meaterial-balance method?
it is the measuring of the chemical-energy content of the organic matter that enters and leaves an animal’s body
what exponent do most organism fall on?
most organisms fall on exponent 0.75 and not 0.67
what is kleiber’s law?
kleiber’s law states that majority of animals’ metabolic rate scales to the 3/4 or 0.75 of the animal’s mass
why do endotherms have a higher metabolic rate than ectotherms?
because they have to thermoregulate
what is the relation between weight-specific resting metabolic rate and body weight?
weight specific metabolic rate decreases with increasing body weight
what is Eactivity?
Eactivity includes most forms of moverment above the resting state
how does the heat generated as activity increases helps the thermoregulation costs of a dormant or resting organism?
when activity increases, the heat generated may cover the thermoregulation costs of a dormant (resting) organism
what is Eproduction?
Eproduction represent both growth and reproduction.
what is the value of Eproduction the an organism has a balanced energy budget?
the value will be zero
what is the happens when an organism has more than enough energy consumed?
Eproduction will be positive and mass will increase
what is the happens when an organism has not enough energy consumed?
Eproduction will be negative and mass will decrease
what is homeostasis?
homeo= similar stasis= state
it is the regulation of an internal environment in the face os changed in the external environment. it is a very dynamic process that is tightly regulated by which the organism can change its bahaviour/metabolism to maintain its internal environment within an acceptable range
what are the parameters that organisms must control?
organisms must control pH, water (volume and pressure of cells and blood plasma, osmoregulation), solutes, temperature, oxygen/carbon dioxide, and heart rate
what is negative feedback mechanisms?
a change in a variable under homeostatic control triggers a response that opposes the change
what is a sensor?
it detects the environmental conditions
what is an integrator?
it analyzes signal from sensor, compares conditions to the set point and activates appropriate effector
what is an effector?
it causes a physiological change that opposes the deviation from the set point
what is posituve feedback mechanism?
a change in a variable under homeostatic control triggers a response that amplifies the change. pushes a system away frim hemeostasis-giid for achieving an outcome, once
what is thermoregulation?
regulating internal body temperature
what is ambient temperature (Ta)?
it is the temperature of the air surrounding a component
what is body temperature?
it is the temperature of an organism
what is heat generated by?
heat is generated by metabolism
how can heat be exchanged with the environment?
through conduction, convection, and radiation
how can body heat or temperature be regulated?
by changing the rate of heat gain and loss
what is conductance?
it is the rate of heat exchange
why do large organisms have lower conductance?
because they have a smaller SA/V ratio
what is homeotherm?
maintains “constant” body temperature (Tb) independent of ambient temperature (Ta). this can be a human (36C) or an earthworm (5C)
what is heterotherm?
Tb fluctuates with Ta. Ex. freshwater fish whose Tb changes with seasonal changes in the water temperature
what is an endotherm?
uses metabolism to generate body heat. (internal heat generation)
what is an ectotherm?
acquires body heat from environment (external heat source)
what is regional heterothermy?
organisms that are able to maintain different temperature zones in different regions of the body
where does thermoregulation occurs?
it occurs above and below the thermal neutral zone to regulate body temperature
what happens below the thermal neutral zone (hypothermy)?
shivering, vasoconstriction, piloerection, decreasing surface area, decreasing exposure (huddling/burrowing)
what happens above the thermal neutral zone (hyperthermy)?
panting, vasodilation, sweating, increasing surface area, decreasing exposure (to sun)
what is behavioural regulation of conductance?
moving to optimize heat exchange with the environment to attain an ideal body temperature
what are long term solutions for thermoregulation?
growing fur/adding fat, shedding, changing colour
what is exposure?
moving into or out of the sun/wind
what is grouping?
huddling together to share radiation
what is dormancy-daily torpor?
-it is a short (6-8 hours) reduction in activity
-about 10 degrees celsius drop in Tb and a lower MR
-reducing spending energy to stay warm (expecially when food is scarce in winter)
-high metabolic rate is turned down nightly/seasonally to reduce energy requirements in cold, drought and famish environments
what is dormancy-hibernation?
-Tb regulated close to Ta
-Massive reduction in metabolic rate
-lasts for about 2 weeks before arousal
-requires massive heat generation for arousal
-awake fir 1-2 days and then repeats
why do bears do not hibernate?
-only 10 degrees celsius lower Tb amd short duration (2-3 days)
-they have a small SA/V, lots of insulation (fat/fur) but food is scarce so they sleep and burn fat.
what is migration?
complete avoidance of poor environmental conditions
what is physiological regulation of conductance?
making physiological adjustments to optimize heat exchange with the environment to attain an ideal body temperature
what is membrane acclimation?
-membrane viscosity is affected by temperature
-different conformation decreases the enzyme’s optimum temperature
-increased enzyme concentrations counter lower activity
-phospholipids change level of saturation
-accumulation of changes in every cell, acclimates the entire organism
what happens when an organism is acclimated to 5 degrees?
there are lots of unsaturated fatty acids and at 25 degrees, membranes are too fluid
what happens when an organism is acclimated to 25 degrees?
there are lots of saturated fatty acids and at 5 degrees, membranes are too viscous