KPE161H1 Lecture Notes - Lecture 3: Intercostal Muscle, High Force, Sarcolemma
9 Mar 2019
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Document Summary
Muscle: 660 muscles in adult human, make up 45% of body weight, site for energy conversion (chemical to mechanical for movement) and energy storage. Important tissue for bioenergetic homeostasis: takes energy stored and converts it into movement. Not enough ct breaks down scurvy: scurvy can lead to death. Important radius of a given muscle fibre: large radius big distance through which oxygen has to pass to mitochondria, fuel substrates (glucose, etc. ) have a longer distance to travel as well. Arrangement of filaments: muscle cells have striped/striated appearance under microscope from structure of myofibrils, myofibrils made of two principle proteins: actin (thin filament) and myosin (thick filament) Contracting muscle fibre: once myosin binds with actin, its shape slightly changes, its head moves backwards pulls actin pieces closer together, head movement shown on last image, atp allows for myosin to release actin.
