The lipid bilayer surrounding the endoplasmic reticulum [goid 5789] [pmid 11402072] [evidence IDA]; A complex system of membrane-bounded compartments located between endoplasmic reticulum (ER) and the Golgi complex, with a distinctive membrane protein composition; involved in ER-to-Golgi transport [goid 5793] [evidence ISS]; Double layer of lipid molecules that encloses all cells, and, in eukaryotes, many organelles; may be a single or double lipid bilayer; also includes associated proteins [goid 16020] [evidence ISS]; Double layer of lipid molecules that encloses all cells, and, in eukaryotes, many organelles; may be a single or double lipid bilayer; also includes associated proteins [goid 16020] [evidence IEA]; Penetrating at least one phospholipid bilayer of a membrane. May also refer to the state of being buried in the bilayer with no exposure outside the bilayer. When used to describe a protein, indicates that all or part of the peptide sequence is embedded in the membrane [goid 16021] [pmid 9405806] [evidence NAS]; A fine reticular network of membrane-limited elements that pervades the sarcoplasm of a muscle fiber; continuous over large portions of the cell and with the nuclear envelope; that part of the endoplasmic reticulum specialized for calcium release, uptake and storage [goid 16529] [evidence ISS]; A relatively pale zone traversing the center of the A band of a sarcomere, visible in relaxed muscle fibers; consists of the central portion of thick (myosin) filaments that are not overlapped by thin (actin) filaments [goid 31673] [pmid 1329967] [evidence IDA]; A region of a sarcomere that appears as a light band on each side of the Z disc, comprising a region of the sarcomere where thin (actin) filaments are not overlapped by thick (myosin) filaments; contains actin, troponin, and tropomyosin; each sarcomere includes half of an I band at each end [goid 31674] [pmid 1329967] [evidence IDA]; The lipid bilayer surrounding the sarcoplasmic reticulum [goid 33017] [evidence IEA]; Cytoplasm situated near, or occurring around, the nucleus [goid 48471] [evidence ISS]