English term (edited): skeletal fast-twitch troponin C gene element

"Ca2+-regulation is essential for muscle contraction and relaxation (Metzger and Moss, 1990). Troponin is the key calcium-dependent regulator of striated muscles (Greaser and Gergely, 1971). The troponin complex is a heterotrimer composed of troponin C (TnC), the Ca2+-binding subunit, troponin I (TnI), the inhibitory subunit, and troponin T (TnT), the Tm-binding subunit. The troponin subunits are encoded by separate genes that have evolved into muscle fiber-type-specific isoforms. Whereas TnC has only two isoforms, one in fast skeletal muscle and the other in cardiac and slow skeletal muscles, TnI and TnT were evolved from a TnI-like ancestor and each has three isoforms for cardiac, slow skeletal, and fast skeletal muscles (Figure 1; Chong and Jin, 2009; Sheng and Jin, 2014). Polyploid vertebrate skeletal muscle cells can express a single class of troponin isoforms in a highly fiber-type-specific manner with coupled expression of slow TnI and slow TnT in pure slow fibers and fast TnI and fast TnT in pure fast fibers (Brotto et al., 2006)."

"BELA SKELETNA MIŠIĆNA VLAKNA (engl. white skeletal muscle fibers, lat. myofibra alba), vrsta mišićnih vlakana koja su mnogo veća od crvenih, ali sadrže manje sarkoplazme, mioglobina i mitohondrija. Miofibrili su veći i jači, ali su Z linije tanje od onih u crvenim. Kontrahuju se mnogo brže od crvenih vlakana, ali se takođe i brže zamaraju. Grade uglavnom mišiće ekstremiteta."