Topic 7 Lecture Flashcards
Ectotherm
Animals that dont regulate body temp
Endotherms
use energy to maintain body temp
Large large require____ but less
higher absolute energy but less energy per gram
as body volume ____, SA _____ more ___
increase
increase
slowly
Scaling
The study of the effect of size on anatomy/physiology
larger animal has smaller ___relative to smaller organisms
SA/V ratio
Organisms exchange matter and generate energy across
membranes (SA)
small sa to volume is disadvantageous to for large organism so they
have highly branched circulatory, respiratory and digestive systems to increase SA
Small Sa to V is advantageous t=for larger animals as
more heat retention
heat is produced by the entire volume and lost through SA
Isometery
Both dimensions remain proportional
Allometry
lengths don’t change equally (baby have bigger heads)
Positive allometry (2)
Anything that scales greater then 1
as one dimension increases, the other increases to a greater proportion
Hypoallometry (2)
As one dimension increases, the other dimension increases to a lesser proportion
scaling <1
Energy In formula
Energy in=E assimilation (energy being used by body) + E excretion
If you eat a kilo of steak and get X amount off kilocalorie from it, the energy is
Ein
E assimilation + the formula *2 formulas
Energy being used, not being wasted
Eassimilated= Ein-Eexcretion
Eassimilated= Erm+Eproduction+Eactivity
What is Eproduction mean?
You are eating a lot so your body stores it as glycogen or protein
growth and producion
Ermr mean?
Resting metabolic rate
energy needed for maintenance, breathing, blood circulation, organ function. Daily routine
the relationship btwn size, sa:V, and energy
smaller the animal, larger the SA:V, ratio, more energy required to meet demand
examples of E excretion
Urine, feces, shedding, heat loss
Herbivoure digestive tract
plant eating animals have longer digestive tract as plant material is harder to digest
Carnivore digestive tract
Carnivores have smaller digestive tract as protein is more easily digestible.
there’s an energy cost to disgisting your food such as
chewing, enzymes (net loss)
SDA Specific dynamic action
extra heat produced or energy spent for digestion/ absorption
Energy Excretion 4 steps
- Food needs to be broken down (chewing/ezzymes) which takes energy
- Nutrients are then absorbed which leads to net gain of energy
- When most energy is absorbed, digestion rate decreases
- All possible energy is extracted, leaving indigestible “dregs” for excretion (Lose some energy)
Why do you need long digestive tract?
Increase SA and absorb more
better quality vs low quality
better quality food requires less energy tp break up the food and derive more energy at a faster rate compared to low quality food
Metabolic rate
a measure of activity/ amount of energy expended
Rate of energy consumption
rate at which it converts chemical energy to heat and external work
3 importance of metabolic rate
- Helps determine how much food an animal needs
- quantitative measurement of total activity of all physiological mechanisms (tells you overall)
- Ecologically helps to determine the pressure on energy supplies in the ecosystems, Ecosystem has number of animals, you measure the metabolic rate of each of these animals and have an idea what total demand is. Gives ideas of how long it can be sustained.
RMR+ includes what
Energy expenditure at rest but routine day to day. include digestion, taking a walk, sweating etc
Basal Metabolic Rate (5)
For endotherms
Amount of calorie you burn from staying active (necessary function)
Metabolism at complete rest-lowest possible
more muscle=higher
absolute lowest measure in thermoneutral zone so NO THERMOREGULATION
Standard Metabolic Rate (SMR) (3)
Ectotherms
SMR will vary with temp so any SMR measurement is specific to the temp at which its taken
ALWAYS SPECIFY TEMPERATURE
Metabolic rate measure at a specific temp
ectotherms can be in diff environments which dictate metabolic rate
SMR and BMR (4)
measure of metabolic rate in animals that are calm at rest and not actively digesting food. needed to sustain life
Field Metabolic rate
Metabolic rate measure in wild animals, free living animals
Homeotherms
maintains constant body temp independent of ambient temp
Poikilotherms
Cannot regulate its body temp except by hiding
BMR of a homeotherm (3)
The animal’s metabolic rate while it is in its thermoneutral zone, fasting, resting
SMR of a poikilotherm
metabolic rate while it is fasting, resting
specific for prevailing body temp
Direct Calorimetry
Measures the rate at which heat leaves an animal’s body: provides measure off energy expended in the form of heat.
expensive + cumbersome
Indirect calorimetry- 2 ways
- measure the rate of respiratory gas exchange with its environment (respirometry)
- Measure the chemical energy content of the organic matter that enters and leaves an animal’s body (Material balance method)
Weight specific MR and body weight relationship
Weight specific MR decreases with increasing body weight
mass specific to absolute
+1
Absolute to Mass specific
-1
Eactivity includes
most forms of movement above the resting state
E production
Both growth and reproduction
if more than enough energy is consumed, the value is + and mass will increase
If not enough energy is consumed, the value is - and mass will decrease
