design rules for plants and animals
obey physical and chemical laws, meet demands but are economical, constrained by evolutionary history
law of energy
energy can't be created or destroyed, entropy (disorder) always increases
milieu internior
constancy of the internal environment is the condition for free life
conformity
cells experience constant conditions, energetically costly
regulation
cells use mechanisms to cope with variability, energetically cheap
zone of tolerance
optimal fitness conditions
homeostasis
constant physiological process with maintain most of the constant states in the organism
negative feedback
returns the value to the set point
negative feedback mechanism
controlled variable effects the sensor which compares the value to the set point and signals for the effectors
positive feedback
reinforces deviations of a controlled variable from a set point
direct proportionality
isometric scaling, y = ax
allometric scaling
y=ax^b
residual analysis
deviation from the average, above or below allometric scaling
catabolism
breakdown of molecules to release energy
anabolism
use of energy to assemble molecules
2nd law of thermodynamics
entropy (disorder) always increases
what type of system is the 2nd law of thermodynamics true for
closed / isolated systems with no energy input
chemical bond energy
Energy liberated or required when atoms are rearranged into new configurations, totipotent, high grade
totipotent
something that can be used for energy work but can't be used to make new chemical energy
electrical energy
energy that a system possess by the separation of positive and negative charges (voltage potential), high grade
mechanical energy
energy of organized motion in which many molecules move simultaneously in the same direction, high grade
heat
energy of random molecular motion, low grade waste
purpose of heat
determines temperature which influences physiological rates but does not do physiological work
calorie
amount of energy to raise the temperature of 1g of water by 1 degree Celcius
power
rate of energy used per unit
Input / Output Budget
All absorbed chemical energy is either stored in chemical energy or eventually converted to heat
biosynthesis
chemical energy is exported organic matter
maintenance
re-synthesizing proteins, pump heart, maintaining body temperature
external work
takes energy and releases heat
metabolic rate
rate at which an animal consumes energy
how is metabolic rate measured
from heat production
direct calorimetry
metabolic rate is measured directly from the amount of heat released by an organism
indirect calorimetry
metabolic is calculated from the oxygen consumed, the carbon dioxide produced, or both
respiratory quotient equation
carbon dioxide produced / oxygen consumed
basal metabolic rate
not expending energy to generate heat, endothermic homeotherms, thermoneutral zone, resting, postabsorptive
standard metabolic rate
BMR for cold blooded animals, ectothermic poikilotherms, fasting, resting, at a defined temperature
field metabolic rate
daily expenditure of a free-living animal
postabsorptive
processing a meal after is also expensive, bump in metabolic rate
specific dynamic action
increase in metabolic rate associated with food indigestion
allometric scaling of metabolic rates
nonlinear scaling
what does temperature limit
where organisms can live and function
temperature
intensity of motion by the atoms in an object
what does temperature determine
direction of heat transfer, from warm to cool
radiation (routes of heat exchange)
heat radiations from objects as infrared light, can emit and absorb
conduction (routes of heat exchange)
transfer of heat through a substance that is macroscopically motionless
convection (routes of heat exchange)
transfer of heat through a macroscopic motion of a substance and requires fluid flow
evaporation (routes of heat exchange)
cutaneous or respiratory
how do plants affect their leaf temperature
transpiration, the exhalation of water vapour
endotherms
generate internal (metabolic) heat
ectotherms
rely mostly on external temperatures to determine body temperature
homeotherms
defend a constant body temperature
poikilotherms
allow body temperature to vary
heterotherms
have more than one temperature set point
regional endothermy/ heterothermy
different body temperature in different parts of the body
q10 ratio
rate of process at one temperature over the rate of the same process at a temperature 10 degrees lower
what type of response does q10 measure
acute responses
when q10 ~1
many physical/ chemical processes, not greatly affected by temperature
when q10 ~ 2-3
most biological processes
how does temperature cause metabolic change to occur
temperature determines rate at which they encounter one another and ten confirmation and efficiency of enzymes
what does vmax mean
active site is full so adding substrates does not speed it up
what is km
amount of substrate required to reach 50% of vmax, measure of how tightly enzymes bind substrates
relationship of affinity and km
inverse
how does protein structure effect temperature
changing the active site can lead to a change of binding affinity which changes the rate of reaction
adaptation
population level, different gene variants
acclimatization
individual level, chronic response
acclimation in the lab
acute response in controlled conditions
compensation
maintaining performance in the face of varying conditions by changing physiology and biochemistry, plasticity
how can compensation work
changing enzymes in a pathway
how do enzymes change to compensate for colder temperatures
make more copies of the enzyme to increase reaction rate
isozyme
change expression depending on environmental conditions
phosphorylation
changes the activity of enzymes and alter rate of reaction
changes in the enzyme environment that alter activity
pH, substrate availability, lipid environment
homeoviscous adaptation
maintain same viscosity across temperature
what increases fluidity of the membrane
short chain lengths and double bonds (unsaturated)
behavioural thermoregulation
body keeps itself in conditions they can tolerate
endothermic homeotherms
maintain a high and stable body temperature using internal heat, cells are wasteful and turnover more heat
thermoneutral zone
range of temperature with no relationship of metabolic rate and temperature outside
who has a minimum energy expenditure
endothermic homeotherms
scholander curve below tnz equation
mr = conductance (body temp - actual temp)
within the tnz, scholander curve
conductance changes and mr is constant
vasomotor responses
dumb heat and send more blood to the skin too keep heat at the core
anastomosis
blood vessels short circuit their path to capillary blood so it never goes to the skin
pilomotor / ptilomtor
puff fur
effect of postural changes or huddling / creche
minimize conductance
countercurrent exchange
anatomical arrangement where heat flows laterally to the venous blood coming back to keep heat close to the core
non-shivering thermogenesis
production of excess heat by futile cycles
upper critical temperature
conductance is maximal, dissipate as much heat as possible
above the upper critical temperature
conductance no longer efficient in maintaining body temperature
thermogenesis in aroids
alternative oxidase pathway
alternative oxidase in the ETC
short circuits transport of electrons, energy is released and heat is produced, production of ATP does not happen
counter-current heat exchanger
blood vessels are tangled in a knot and carry blood warm blood through the rete
movement of heat in counter-current heat exchanger
heat moves from hot to cold vessels and stay towards the centre
regional endothermy in bony fish
warm eyes and regions of the brain, futile cycling of calcium
metabolism
degradative, creates ATP, important for energy balance and homeostasis
photosynthesis impact of atmosphere
increase in carbon dioxide concentration in the atmosphere
light dependent reaction
energy input from photons, uses oxygen production to measure photosynthesis
light dependent reaction molecules
uses water, adp, nadp, produces atp, nadph, oxygen
light independent reaction
energy input from light dependent reactions, use net carbon dioxide consumption to measure rate of photosynthesis
light independent reaction molecules
uses co2, atp, nadph, produces adp, nadp, sugar
energy equation
1/ wavelength