PSIO 201 Final: Psio201finalreview

• School: University of Arizona
• Department: Physiology
• Course: PSIO 201
• Professor: Claudia Stanescu, Douglas Keen

Document Summary

Block 1: introduction and cellular function: define homeostasis and describe the elements that comprise a feedback loop. Identify a representative example of a positive vs. a negative feedback loop, and explain why one category is called positive" and the other is called negative. ". Homeostasis: relative constancy of the internal environment; the physical and chemical parameters of living organisms (ie temp, ph, concentrations) tend to remain constant over time. Negative feedback loop: regulating body temperature in a room (example) Definition: original stimulus reversed; most feedback systems are negative; used for frequent adjustment. Compare and contrast integral and peripheral membrane proteins. Amphiphilicity" of phospholipid & protein structure is important in establishing stable membrane structure. Integral membrane proteins: extend into or completely across cell membrane; are. Amphipathic with hydrophobic portions hiding among the phospholipid tails of the lipid bilayer. Peripheral membrane proteins: attached to either inner or outer surface of cell membrane and are easily removed from it.