BIOL 430 Lecture Notes - Lecture 28: Myosin, Cellular Respiration, Axon
Document Summary
Red due to myoglobin (primary o2-carrying molecule in muscle) For endurance, fires slowly (~110 msec) for sustained contractions -red due to large blood supply large number of mitochondria for slow, oxidative metabolism (low glycogen, high fat stores) Myosin heavy chain type 1 -slow to fatigue. Fast twitch- type 2a and 2b, large diameter. For fast response, rapid contractions (~50msec) -fast oxidative (2a) and glycolytic metabolism (2b) (high glycogen, low fat stores) -easily fatigued. Myosin heavy chain type 2a or 2x , 2c. Different motor fibers that live within the cell. Within fasiculated bundle of nerve cells - up to three diff types of fibers within. Use lots of oxygen lots of myoglobin (isoform of hemoglobin) > a way store excess oxygen large numbers of mitochondria (enough time to oxidize atp) Myosin molecules come in different types (heavy chain type 1) For endurance activities (going for a walk, posture) Easily fatigued (run out of oxygen quicker)
