A protein (of size 42 kD) and one of the major components of the actomyosin motor First isolated from striated muscle and often referred to as one of the muscle proteins
A motor protein Actin forms the backbone of the thin filaments of striated muscle cells and is also involved in other cellular motions, such as the movement of growth cones
A protein, along with myosin, the main component of muscle Molecules of actin come together (polymerise) to form long filaments In muscle the filaments are very regularly aligned Muscle exerts force as a result of myosin filaments sliding along filaments of actin in a way that is driven (or fuelled) by energy produced by the hydrolysis of ATP This sliding is a one way process and causes the muscle to become shorter The muscle can be "reset" by being lengthened again as another muscle contracts, hence muscles always work in pairs so that they reset one another
A protein found in many cells Actin assembles into long polymer rods called microfilaments These microfilaments form part of the cell's cytoskeleton and they interact with myosin to cause movement in muscles In muscle contraction, filaments of actin and myosin alternately unlink and chemically link in a sliding action The energy for this reaction is supplied by adenosine triphosphate (ATP)
One of two proteins responsible for contraction of muscle cells and the motility of other cells. It occurs as a monomer, G-actin, a globular protein, and in living cells as a polymer, F-actin, which resembles two strings of beads twisted around each other into thin filaments. The filaments occur in regular structures, alternated and interwoven with thick filaments that contain myosin, the other major muscle protein. The thick and thin filaments slide past each other, under the control of calcium ions, resulting in contraction (shortening) and relaxation (lengthening) of the muscle cells
the smaller of the two contractile elements which sustain damage through applied resistance and are once again repaired through anabolism resulting in hypertrophy of the myofibril