Bio 241 final exam

energy demand

energy is needed in organisms for maintenance, growth, and reproduction

what does energy demand depend on?

body size, activities, environment (temperature)

ectotherm

cold blooded animal, whose body temperature varies with the temperature of its surroundings

endotherm

warm blooded animal, whose body controls and regulates its temperature by controlling the internal heat it produces

the study of anatomy/physiology is called?

scalling

surface area proportional to

length^2 (squared)

volume is proportional to

length^3 (cubed)

length is proportional to

surface area ^1/2 or volume ^1/3

what supports mass in an organism?

need to obtain resources and excrete waste

how is small SA:V ratios a disadvantage to large things?

- nutrient exchange- highly branched circulatory/respiratory/digestive systems that increase SA

how is small SA:V ratios an advantage for large things?

- heat protection- heat produced by V and lost by SA

scaling relationships (power and log transformed functions)

Y=aX^b / log Y = b(log X) = log a

why should we log transform scaling relationships?

data normalization/used to make power function linear

isometry

both dimensions remain proportional b=1(.98~1.02)ex-\> slope of heart growth (b=0.98)

positive allometry (hyperallometry)

as one dimension increases the other increases to a greater proportionb=1+ex-\> crab (b=1.57)

negative allometry (hypoallometry)

as one dimension increases the other decreases to a lesser proportionb=-1ex-\> slope of brain as we grow (b=0.73)

energyIN=

energyASSIMILATION+energyPRODUCTION
energyRMR+energyACTIVITY+energyPRODUCTION+energyEXCRETION

energyASSIMILATION=

energyRMR+energyACTIVITY+energyPRODUCTION+energyEXCRETION
energyIN-energyEXCRETION

larger organisms

- need more food- greater eIN per unit time- eat more food at a given time- eat less often-take in more air per breath- pump more volume blood per heartbeat- lower breathing/heart rate- smaller SA:V

measure of evolutionary fitness

total amount and rate at which things obtain energy from food

retention time

time it takes for food to pass through digestive tract, phenotypic trait on environment

is food that remains in the stomach longer more or less nutritious ?

less

how is food excreted?

food broken down by chewing (-energy)
nutrients absorbed (+energy)
energy absorbed = digestion rate decreases
all possible energy extracted leaving dregs
dregs excreted

why are digestive tracts long?

increase SA:V

RMR

resting metabolic rate, energy consumption, heat, calories

most accurate way to take energyRMR

heat loss/gain measured in calories or joules

BMR

basal metabolic rate- least possible rate, at complete rest

SMR

standard metabolic rate - ectotherms rate at specified temperature

FMR

field metabolic rate - measured in wild animals

direct calorimetry

measures rate heat leaves body,

indirect calorimetry

o2 consumed/co2 produced, measures rspirometry

kleibers law

metabolic rate is proportional to m=aW^3/4
m=total metabolic rate
log m = log a + blog w

energy ACTIVITY

movement above resting rate, activity increases heat, covers costs for resting

energy PRODUCTION

represents growth and reproduction,

if energy budget is balanced what will energyPRODUCTION be?

0

if more energy is consumed, what energyPRODUCTION?

positive, +mass

if not enough energy consumed, what energyPRODUCTION?

negative, -mass

homeostasis

regulation of an internal environment in response to the external environment

what different kinds of parameters do organisms need to control in order to maintain homeostasis ?

ph, water, blood pressure, osmoregulation, solutes, temp, o2/co2, heart rate

negative feedback mechanisms

change in variable under homeostatic control that triggers a response that opposes the change

three parts to a negative feedback chain

sensor, integrator and effector

what does the sensor do in a negative feedback chain?

detects environmental conditions

what does the integrator do in a negative feedback chain?

analyses signal from sensor and compares conditions to set point, then activates appropriate effector

what does the effector do in a negative feedback chain?

causes physiological change that opposes deviation from set point

positive feedback mechanisms

change in variable under homeostatic conditions that control triggers to response that amplifies change

example of positive feedback chain ?

birth

what is the integrator whilst giving birth?

pituitary gland that releases oxytocin

what is the effector whilst giving birth?

oxytocin causing uterus to contract, puts pressure on the uterus

thermoregualtion

regulating body temperature

ambient temperature (Ta)

the temperature of the surrounding environment.

body temperature (Tb)

the amount of heat in the body that is a balance between the amount of heat produced and the amount lost by the body

body heat is generated by

metabolism

body heat can be regulated by

changing conductance

conductance

rate of heat exchange

homeotherm

maintains constant body temperature

heterotherm

variable body temperature, Tb fluctuates with Ta

regional heterothermy

parts of body vary in temperature

adaptation of regional heterothermy

countercurrent heat-exchange system

hypothermy

decreasing body temperature, causes you to shiver (below TNZ)

hyperthermy

increasing body temperature, causes you to pant (above TNZ)

low conductance is a adaptation for

heat retention

high conductance is an adaptation for

heat loss

behavioral regulation of conductance

moving to optimize heat exchange with environment to attain ideal body temp

exposure in relation to conductance

movement in or out of sun, surface area-\> lizard basking in sun

grouping in relation to conductance

huddling together to share radiation-\> penguins

dormancy

daily torpor, reducing your RMR to preserve heat and reduce E requirementshibernation, massive reduction in RMR

do bears hibernate?

no

migration

complete avoidance of poor environmental conditions

physiological regulation of conductance

making physiological adjustments to optimize heat exchange with environment to attain ideal body temp

membrane acclimation

physiological changes that occur in response to seasonal temperature changed, change cellular conditions to work optimally in cold/warm environments
helping membranes not be too fluid or viscous

blood flow

vasodilation/vasoconstriction

vasodilation

increase in conductance with environment,
endotherms- when hot to release heatectotherms- when cold to increase heat gained from environments

vasoconstriction

decrease in conductance with environment,
endotherms- when cold to retain heatectotherms- when got to retain heat

insulation

internally(fat/blubber), externally(fur/feathers), piloerection (fluffing /increasing thickness of layer)

fur/feather thickness/length

better insulator, change thickness seasonally,

fur colouration

-dark fur absorbs light and generates heat-white fur allows light to reach skin + generates heat-black skin + white fur best for heat retention-hollow hairs allow radiation to transmit down hair shaft

sweating and panting

heat loss due to evaporation

cryoprotectants

molecules produced to lower freezing point, allow ice to form not internally-\> frog, hamsters

antifreeze proteins

ice nucleating agents, prevents ice formation

shivering thermogenesis

action of antagonistic muscles generates heat without causing movement

non-shivering thermogenesis

special (brown) fat tissue that is loaded with special mitochondria, used to generate heat instead of e- released in transit for ATP it is sent through UCP! which releases more of the energy as heat

MRmax

max metabolic rate

MRsus

sustained metabolic rate

what would be used first in quick physical movements ?

pools of ATP in cells

what would be used second in quick physical movements ?

phosphocreatine (PCr) used to replenish ATP

what will be used third and help maintain physical movements?

glycolysis

what will be used lastly to help maintain physical movements?

oxidative phosphorylation

o2 debt

use up cellular pools of ATP/PCr and produces lactic acid

recovery metabolism

replenishes ATP/Pcr and removes lactic acid

mass relationship to active MRmax

smaller mass = lower MRmax, larger max = higher MRmax

mass relationship to mass specific MRmax

smaller mass = high MR, larger mass = low MR

metabolic scope

capacity for activity,MRmax/RMR or MRsus/RMR

scope will be simmillar between ...

ecto/endotherms of simmillar mass

mass specific metabolic rate

way of measuring locomotion, energy (o2 volume) required to move one unit of mass of organisms, as velocity increases

cost of transport

way of measuring locomotion, energy required to move one unit of an organism one distance, as velocity increases

what effects Eactivity

inertial forces, momentum forces, drag forces,

inertia

tendency of mass to resist motion

momentum

tendency of moving mass to sustain velocity

drag

force generated by opposite direction of things movement

do large or small things overcome drag better?

large,-\>mosquito vs elephant