BIO271H1 : BIO271 - Respiration Section.docx
Document Summary
Respiration exchange of oxygen and carbon dioxide between the external environment and the mitochondria. Mitochondrial respiration: production of atp through oxidation of carbs, aas, or fatty acids; o2 consumed, co2 produced. External respiration: gas exchange at the lungs. Gill bailer (negative pressure in branchial chamber sucks water across gills) Air flow unidirectional tidal tidal countercurrent tidal unidirectional. Buccal cavity contracts forcing water past gills and out. Mouth open, opercular valve closed, buccal cavity expands. Gill slits spiracles countercurrent countercurrent countercurrent unidirectional tidal unidirectional unidirectional mouth. Opercular valve opens and opercular cavity compresses. 2 cycles of inhalation and exhalation posterior air sac lungs anterior air sacs out trachea. Unidirectional or tidal tidal unidirectional mouth mouth crosscurrent unidirectional. Unicellular organism generally rely on diffusion larger organisms rely on bulk flow and diffusion: ventilation moving air over a respiratory surface, circulation transporting gases in the circulatory system.
