Supported by. Pat Tillman walked away from a lucrative career in the National Football League to join the military and fight in Afghanistan, where he was ultimately killed by friendly fire in an incident that was initially covered up.
A membrane-enclosed sac that is part of the endomembrane system of a eukaryotic cell, having diverse functions. central vacuole. A membrane-enclosed sac occupying most of the interior of a mature plant cell, having diverse roles in reproduction, growth, and development. peroxisome. sac made of membrane in the cytoplasm of a eukaryotic cell. endoplasmic reticulum (ER). An extensive membranous network in a eukaryotic cell, continuous with the outer nuclear membrane and composed of ribosome-studded (rough) and ribosome-free (smooth) regions.
A vacuole is a membrane-bound organelle which is present in all plant and fungal cells and some protist, animal and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in solution, though in certain cases they may contain solids which have been engulfed. Vacuoles are formed by the fusion of multiple membrane vesicles and are effectively just larger forms of these. The organelle has no basic shape