ThermoregulationWhat is temperature?

ThermoregulationWhat is temperature?

Measure of the mean kinetic energyIntrinsic property- independent of object characteristics size, mass etc

Liquid/Gas Solid

Heat capacity or thermal mass?

Measure of the ability of a substance to store heat kJ g-1

Extrinsic property = varies with characteristics of objectSize, mass, volume etc

Thermoregulation

Death Valley Pup Fish Death Valley

Trematomous- Antarctic notothaenidAntarctica

Life Exists Within a Narrow Range

Uniqueness of WaterHydrogen Bonds

Freezes at 0 °CEvaporates at 100 °C

Heat of vaporization = 540 cal/ml or 40.65 kJ/mol

Heat of fusion = 79.82 cal/g or 333.55 kJ/g

Heat content = 1 cal/g or cp = 75.3 J K−1 mol−1

Heat of vaporization of H2O, is more than five times the energy required to

heat the same quantity of water from 0 °C to 100 °C

Colligative Properties of water

Common Compunds

Amm

onia

Buta

ne

Etha

nol

Hydr

ogen

Met

hane

Met

hano

l

Prop

ane

Phsp

hine

Wat

er

Hea

t of v

apor

izat

ion

kJ k

g-1

0

500

1000

1500

2000

2500

Heat of Evaporation

Amm

onia

Buta

ne

Etha

nol

Hydr

ogen

Met

hane

Met

hano

l

Prop

ane

Phos

phin

e

Wat

er

Hea

t of f

usio

n (m

eltin

g) (c

al g

-1)

0

20

40

60

80

100

Melting Point

Etha

nol

Met

hane

Met

hano

lPr

opan

eW

ater

Etha

neG

lycer

olFo

rmic

aci

dAc

etic

aci

dAc

eton

eBe

nzen

eM

yris

tic a

cid

Palm

itic

acid

Stea

ric a

cid

Para

ffin

wax

Hea

t of F

usio

n (c

al g

-1)

0

20

40

60

80

100

The heat of fusion can also be used to predict solubility for solids in liquids.

Provided an ideal solution is obtained the mole fraction (x2) of solute at saturation is a function of the heat of fusion, the melting point of the solid (Tfus) and the temperature (T) of the solution:

Thus the higher the heat of fusion the higher the solubility!Water has very high heat of fusion = high solubility

Thus Water is an Excellent Solvent!!

Water as a Solvent

Pressure

Not an issue for organisms that live at or near sea level

How Much of the Available Habitat is at Sea Level?

Dumbo Squid

Angler FishGiant Deep Water Isopod

The world's deepest fish (Abyssobrotula galatheae) was found in the Puerto Rican Trench at a depth of 8,372

meters

160 180 200 220 240 260 280 300 320

Day (julian)

1000

800

600

400

200

Dep

th (m

)Elephant Seal Foraging Trip

Blainville’s Beaked Whale

11 meters

Hooker et al PRS 2012

Considerable Variation in Foraging Depths

Gibbs Free Energy

ΔG = ΔH – TΔS + PΔV

Where:ΔG = free energy of reactionΔH = change in enthalpyΔS = change in entropyT = temperatureP = pressure

Temperature Effects Q10

Temperature

Potential for Biochemical Adaptation is Limited

Somero et al 1996

Temperature Adaptation

Membrane Fluidity

Varies with

Temperature and Pressure