Any Process That Results in a Change in State or Activity of a Cell (in Terms of Movement Secretion Enzyme Production Gene Expression Etc.) As a Result of a Stress Acting At the Endoplasmic Reticulum. Er Stress Usually Results From the Accumulation of Unfolded or Misfolded Proteins in the Er Lumen.
The Irregular Network of Unit Membranes Visible Only by Electron Microscopy That Occurs in the Cytoplasm of Many Eukaryotic Cells. the Membranes Form a Complex Meshwork of Tubular Channels Which Are Often Expanded Into Slitlike Cavities Called Cisternae. the Er Takes Two Forms Rough (or Granular) with Ribosomes Adhering to the Outer Surface and Smooth (with No Ribosomes Attached).