Thermoregulation in Endotherms and Ectotherms

These flashcards cover key concepts from the lecture notes regarding thermoregulation, including definitions of enzymes, endotherms, ectotherms, and their respective physiological adaptations.

What is the thermal niche for enzymes?

The temperature range in which enzymes function properly; changes shape with temperature.

What happens to enzymes at low temperatures?

Enzymes become less flexible and less functional.

What is acetylcholinesterase?

An enzyme that turns off neurons and is involved in message transmission in the nervous system.

How do endotherms maintain enzyme function?

By maintaining stable body temperatures for peak enzyme productivity.

What is the main disadvantage of being an endotherm?

Maintaining an elevated body temperature is energetically expensive.

How do ectotherms regulate their body temperature?

They depend on ambient temperature, which affects development and growth.

What is the difference between r-selected and k-selected species?

R-selected species produce many offspring with little parental care; k-selected species produce fewer offspring with high parental care.

What is metabolic heat production?

The process by which organisms generate heat to maintain their body temperature through metabolic processes.

What adaptations help endotherms in cold environments?

Fat, blubber, fur, and feathers that aid insulation.

What is countercurrent heat exchange?

A mechanism where warm blood flows alongside cold blood, minimizing heat loss in extremities.

What are some adaptations of ectotherms for thermoregulation?

Behavioral thermoregulation, such as burrowing or basking.

How do some reptiles exhibit parental care?

Certain reptiles guard their eggs or provide nourishment in the form of dead eggs.

What role does body size play in thermoregulation?

Larger body size in endotherms aids in heat retention and metabolic efficiency.

Why are larger endotherms better suited for cold terrestrial ecosystems?

They can maintain stable body temperatures and are insulated better than ectotherms in cold conditions.

What is mesothermy?

A physiological state where animals can raise their body temperature above the ambient environment but lack full regulation of it, often observed in certain large or specialized species.

How do some aquatic endotherms like sharks regulate their body temperature?

By using countercurrent heat exchange to keep muscle temperatures higher than surrounding water.