Hvornår fungerer en proteinpumpe inden i en celle?
Sarcoplasmic reticulum
SR indeholder ionkanalpumper i membranen, som er ansvarlige for at pumpe Ca2+ ind i SR. Da calciumionkoncentrationen i SR er højere end i resten af cellen, kan calciumionerne ikke frit strømme ind i SR, og derfor er der brug for pumper, som bruger energi, som de får fra et molekyle kaldet adenosintrifosfat (ATP). Disse calciumpumper kaldes Sarco(endo)plasmic reticulum ATPaser (SERCA). Der findes en række forskellige former for SERCA, hvor SERCA 2a primært findes i hjerte- og skeletmuskulaturen.
Sarcoplasmic reticulum
The SR contains ion channel pumps, within its membrane that are responsible for pumping Ca2+ into the SR. As the calcium ion concentration within the SR is higher than in the rest of the cell, the calcium ions won't freely flow into the SR, and therefore pumps are required, that use energy, which they gain from a molecule called adenosine triphosphate (ATP). These calcium pumps are called Sarco(endo)plasmic reticulum ATPases (SERCA). There are a variety of different forms of SERCA, with SERCA 2a being found primarily in cardiac and skeletal muscle.
Sarcoplasmic reticulum