2601 Midterm

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