thermal physiology

Question 1

what are the rate enhancing and destructive effects of increasing temperature

Answer 1

rate enhancing - kinetic energy of molecules
destructive - denaturing

Question 1

what re the 2 equations for temperature quotient

Answer 1

Q10 = rate at T / (rate at T - 10)

Q10 = (k2 / k1) ^ (10 / (t2 - t1))
where k = rate and t = time

Question 2

what is the equation for logQ10

Answer 2

(logk2 - logk1) * (10 / (t2 - t1))

Question 3

what are the 2 types of classifying thermo-regulation stratergies

Answer 3

based on the source of body heat (ecto and endo therms)
based on the stability of body temperature (poikilothermy and homeothermy)

Question 3

what are ectotherms

Answer 3

body temp dependent on heat transfer from / to environment

Question 4

what are endotherms

Answer 4

body temp dependent on internal (metabolic) sources of heat

Question 5

what is poikilothermy

Answer 5

body temp varies with environment

Question 6

what is homeothermy

Answer 6

body temp maintained within narrow range

Question 7

are most ectotherms poikilotherms or homeotherms

Answer 7

poikilotherms

Question 8

how can homeotherms control their temperature

Answer 8

behaviourally

Question 9

name a common regulatory ectotherm (homeotherm)

Answer 9

lizards

Question 10

what behaviour can homeotherms engage in to increase temperature

Answer 10

basking

Question 11

what is the role of the capillaries in controlling temperature of homeotherms

Answer 11

vasoconstriction - constriction of capillaries to reduce heat loss
vasodilation - more blood to external capillaries encourages heat loss to environment

Question 12

how is the phospholipid membrane affected by temperature change

Answer 12

too viscous when too cold and too fluid when too warm

Question 13

what is the name of the adaptation to combat phospholipid membranes being impacted by temperature change and what does it involve

Answer 13

homeoviscous adaptation to saturate and desaturate lipids in the membrane

Question 14

what advantage do unsaturated phospholipids provide

Answer 14

membrane can’t pack as tightly, making it more fluid

Question 15

what would a warm adapted animals phospholipid membrane look like

Answer 15

have more saturated fatty acids and cholesterol for stability - giving the membrane more rigidity

Question 16

reference for homeoviscous adaptation

Answer 16

fly experiment - Cooper et al, 2012

Question 17

what animal was used to demonstrate seasonal enzyme activity

Answer 17

alligator

Question 18

what happens to metabolic enzyme activity when colder

Answer 18

metabolic rate decreases when cold causing compensatory increase in enzyme activity

Question 19

what proteins offers thermal protection

Answer 19

heat shock proteins

Question 20

what are the main heat shock proteins

Answer 20

Hsp40, 70 ans 90

Question 20

what is the role of heat shock proteins

Answer 20

re-fold damaged proteins

Question 21

reference for freeze-tolerance

Answer 21

wood frog in Alaska - Larson et al. 2014

Question 21

give an example of animals which use freeze-avoidance

Answer 21

polar fish and invertebrates

Question 21

what allows the wood frog to be freeze-tolerant

Answer 21

glucose and urea are effective cryo-protectants allowing the frog to be completely frozen and immobile

Question 22

how does freeze-avoidance work

Answer 22

anti-freeze glycoproteins prevent uncontrollable ice crystal growth

Question 23

advantage and disadvantage of endothermy

Answer 23

adv - high constant metabolic rate dis - high energetic cost

Question 24

what is special about endothermy evolution

Answer 24

independently evolved in mammals, birds and other taxa

Question 25

do birds or mammals have higher body temperature and why

Answer 25

birds are higher due to energy expensive flying making it easier to be warm than cool down

Question 25

3 ways endotherms gain external heat

Answer 25

basking, migration / movement increase absorbance e.g. being darker in colour, fur and feathers

Question 26

give an example of an animal which uses migration to stay warm

Answer 26

humpback whale moving from the North in summer and moving down to warmer climates in winter to rear offspring

Question 27

3 ways endotherms retain internal heat

Answer 27

vasoconstriction, insulation, counter-current exchange

Question 28

give 2 examples of insulation

Answer 28

anatomical - increased fat and fur behavioural - huddling and burrows

Question 29

give another name for counter-current exchange

Answer 29

rete mirabile

Question 30

how does counter-current exchange work

Answer 30

counter-current flow of veinal and arterial blood arterial blood flows close to vein blood, heat transferred to returning vein blood

Question 31

3 ways endotherms can generate more internal heat

Answer 31

higher base metabolic rate, muscular activity e.g. shivering, non-shivering thermogenesis

Question 32

what is responsible for non-shivering thermogenesis in mammals and birds

Answer 32

brown adipose tissue (BAT) in mammals white muscle in birds

Question 33

how does non-shivering thermogenesis work

Answer 33

breakdown of triglycerides into free fatty acids interact with uncoupling protein 1 causing mitochondria to directly produce heat instead of ATP

Question 34

5 ways to reduce excess heat

Answer 34

reduce insulation e.g. shed fur, vasodilation, evaporation e.g. sweating or panting, counter-current exchange, avoidance

Question 35

give an example of counter-current exchange to remove excess heat

Answer 35

gazelles cool arterial blood going to the brain

Question 36

what are heterotherms

Answer 36

generate internal heat but have variable body temperature

Question 37

give an example of a heterotherm and how it uses counter-current exchange

Answer 37

tuna - preserves warmth in aerobic swimming muscles usingn counter-current rete system

Question 38

give an example of a temporal heterotherm

Answer 38

deer mouse

Question 39

what happens in temporal heterothermy

Answer 39

daily torpor - high body temperature and metabolic rate when active, drops when not

Question 40

what general trends are occuring as a result of climate change

Answer 40

smaller body size, shifts in timing of reproduction, changes in species distribution

Question 41

what are 2 constraints of adapting to climate change

Answer 41

energetic trade-offs e.g. reproductive fitness and immunity reduced capacity to tolerate other environmental stressors e.g. pathogens and pollution