Metabolism

Question 1

metabolism

Answer 1

total of the chemical processes in an organism
-driven by energy flow through an organism
-populations of organisms evolved by being better adapted at utilizing energy

Question 2

exergonic reaction

Answer 2

chemical reactions in which energy is released, ex> oxidation of glucose
glucose + oxygen-> CO2 +water

Question 3

endergonic reactions

Answer 3

chemical reactions in which energy is required
ex: photosynthesis
-catabolic=breakdown
-anabolic=synthesis

Question 4

ectotherms

Answer 4

obtain heat from the environment
ex:inverts., fishes, & reptiles but some insects are endothermic

Question 5

endotherms

Answer 5

can make heat using energy from their metabolism: ATP production and usage such as voluntary muscle contraction(moving around or involuntary shivering) ex: birds and mammals

Question 6

difference between regulators vs. conformers

Answer 6

regulators costs ATP

Question 7

temperature homeostasis cycle

Answer 7

body temp increases->hypothalamus activates cooling mechanisms-> sweat glands secrete sweat & blood vessels dilate, capillaries fill with warm blood and heat radiates from skin surface-> body temp decreases

body temp decreases-> hypothalamus activates warming mechanisms-> blood vessels in skin constrict, diverting blood from skin to deeper tissues and reducing heat loss from skin surface AND skeletal muscles rapidly contract causing shivering which generates heat-> body temp increases

Question 8

how can you measure metabolic rate?

Answer 8

calories produced or heat loss, but best way is oxygen consumption or carbon dioxide production

Question 9

effects of body size on metabolic rate?

Answer 9

small animal-> smalla mount of oO2 consumed; mass-specific metabolic rate= small bodied animals is higher

Question 10

why is metabolic rate inversely proportional to body size?

Answer 10

greater SA:V in small bodies means greater heat loss
*does not explain why ectotherms show same curve

Question 11

metabolic rate vs. temp ECTO

Answer 11

when MR increases, so does temp.
when temp is too hot, starts to shut down

Question 12

metabolic rate vs. temp ENDO

Answer 12

high-> decrease(zone of metabolic regulation) ->evening out(thermal neutral zone) -> increase(zone of heat dissipation

Question 13

camel adaptations:

Answer 13

1) large body size=small SA:V ratio, so large desert mammals do not lose much water to evaporation
2)camels store heat by increasing body temp during the day then disspiate by radiation the heat at night when it is cooler.
3) heat storageis also good bc if you increase body temp in the day, you reduce heat gain from environment and then this reduces evaporative water loss
4)fur insulation reduces heat gain from the environment. same idea as home insulation

Question 14

kangaroo rat adaptations

Answer 14

1) lose lots of water to evaporative cooling because of increased SA:V but, kangaroo rats never drink water bc 90% of water comes from metabolism
2) msut go into shade or burrow to cool
3) many are nocturnal
4) concentrated urine bc it reasborbs the water

Question 15

2 types of torpor

Answer 15

1) hibernation: reduced body temp, reduced MR, respiratory rate-> adaptive for cold conditions bc it would require food
*done by small mammals and birds
2) aestivation: summer torpor, in response to hot dry conditions.
* found in some frogs, tortoises, salamanders, lungfishes, and snails(cluster together to maintain micro humidity humidity

Question 16

How do we make metabolic heat?

Answer 16

1) hydrolysis of ATP-> ADP +inorganic phosphate is highly exergonic
2) shivering: short bursts of muscle contraction
3) oxidation of glucose

Question 17

conduction

Answer 17

direct transfer of heat from an object or to an object

Question 18

radiation

Answer 18

gain heat from exposure to radiant energy(sunlight)

Question 19

convection

Answer 19

loss of heat from moving ar ir water across a surface (e.g. wind chill factor)

Question 20

evaporation

Answer 20

loss of heat as liquids turns to gas(evaporative cooling); harder to do in humid conditions

Question 21

snowshoes hares

Answer 21

blood vessels in ears are constricted, tinier and furry

Question 22

desert jackrabbits

Answer 22

radiation by ears, lose heat to outside to cool off

Question 23

ways of conserving heat

Answer 23

*countercurrent heat exchange(arrangement of arteries and veins)->in duck feet, whale flippers, some fish, humans
*exchange of heat between warm arterial blood with cold venous blood

Question 24

ways to thermoregulate

Answer 24

1) increase insulation
*dogs/cats maintain heavy coat in winter and shed in summer
*marine mammals have thick blubber
*polar beats have fur&blubber, but fur loses power if it gets wet
2) behavorial responses
*social aniamsl huddle
*birds fly south
* birds preening feathers
*dogs panting to cause evaporative heat loss