BIO 3303 Study Guide - Myoepithelial Cell, Pharyngeal Muscles, Cardiac Muscle
Document Summary
Muscle diversity evolved in conjunction and respiratory and circulatory systems (sa:v ratios) Multiple muscle gene formation isoforms allow muscle diversification and specialization. Mechanoreceptors that use the energy of atp hydrolysis to move along cytoskeletal tracks: kinesins- move towards plasma membrane (+ end, dyneins move towards cell body (-end) Involved in intracellular transport like vesicular trafficking. Undergo conformational change; head attaches to change conformation and then bends to pull cargo along the mt. Motor protein myosin head: atp-ase activity, provides energy for mouvement tail: binds cargo, intracellular components or cell membrane neck: regulates head function. 2 myosin isoforms: myosin 1 (monomers) and myosin 2 (dimers) light chains: proteins that associate with the neck activity regulated by reversible phosphorylation. Myosin 2 is associated with essential and regulatory light chains. Atpase: converts energy released from atp hydrolysis into mechanical energy. Cycles of extension, grasping, and bending to pull forward. Energetically costly (especially bend and pull stage)
