BIS 2B Lecture Notes - Lecture 5: Ectotherm, Carbon Fixation, Cardiac Glycoside

• School: UC-Davis
• Department: Biological Sciences
• Course: BIS 2B
• Professor: Schmitt Johanna

Document Summary

Adaptation: evolutionary change in genotype that increases performance. Acclimation: change in phenotype within an ind lifetime to increase performance (often reversible) Inuit people have lived above artic circle for 10,000+ years. Barrel-shaped bodies, short limbs, subcutaneous fat all over, shunt blood to extremities. Biochemical processes (including enzyme-mediated reactions) are often temperature dependent. Enzymes and proteins denature at high temperature, losing their ability to catalyze reactions losing their ability to catalyze reactions. Maximal reaction rate occurs at an intermediate temperature. Optimal enzymatic activity may correspond to optimal muscle performance. Ectotherms: body temperature defined primarily by external conditions. Can regulate temp even though it is not internally. Endotherms: body temp determined primarily by internal, metabolic activity. Ectotherm trying to regulate body temp exposing darkly pigmented back to the sun increases heat gain by radiation. Mechanisms of temp regulation in plants: heat loss by dessert plants. Endotherms primarily use their own source of heat to regulate body temp, they also use behavior.