BIOL273 Midterm: Chapter 12 textbook material to midterm only chapter 12 to midterm only

• School: University of Waterloo
• Department: Biology
• Course: BIOL273
• Professor: Katherine Wood

Document Summary

Pair of antagonistic muscles in arm: biceps brachii (front) flexor moves dumbbell toward shoulder, triceps brachii (back) extensor lower dumbbell weight. One muscle contracts and shortens and the antagonistic muscle lengthens. Myofibrils are the contractile structures of a muscle fibre. Myosin motor protein with ability to create movement: various forms. Determine muscles speed of contraction: made up of a tail and a head with a hinge to allow then to swivel around their point of attachment. 250 myosin molecules join in skeletal muscle thick filament: arranged for myosin heads cluster at one end, central region of filament is the bundle of myosin tails. Actin protein that makes up the thin filaments of muscle fibre: one actin molecule is a globular protein (g actin) Polymerize to make long chains f actin. Two f actin polymers twist together creating the thin filaments of the myofibril.