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.
Plasma Membrane â Plant Cells. The plasma membrane is a selectively permeable membrane made up of a lipid bilayer and proteins surrounding the cell but inside the cell wall. Explore the process, structure, and function of a plant cellâs plasma membrane with this interactive tutorial. Chapter: Cell Membranes.