Rough Endoplasmic Reticulum (RER) Structure composed of a lipid membrane with membrane bound ribosomes lipid membrane is continuous with nuclear membrane Function synthesis of secretory proteins e.g. peptide hormones addition of N-linked oligosaccharides to peptides Cell biology RER is found in high concentration in neurons termed Nissl bodies stain basophilic synthesize/secrete peptide neurotransmitters in prepackaged vesicles pancreatic acinar cells synthesize/secrete digestive enzymes Smooth Endoplasmic Reticulum (SER) Structure lipid membrane without membrane bound ribosomes Function steroid synthesis detox of chemicals makes compounds water soluble two mechanisms hydroxylation via cytochrome P450 hydroxylase complex conjugation involves binding of polar moiety (e.g. glucuronate via glucuronyl transferase) to toxin lipid metabolism release of fatty acids from triglycerides assembles lipoproteins for release carbohydrate metabolism gluconeogenesis allows free glucose to be released into circulation during fasting by removing phosphate from glucose-6-phosphate mediated by glucose-6-phosphatase deficient in von Gierke's disease glycogen storage disease type I presentation accumulation of glycogen in kidney and liver hepatomegaly hypoglycemia Cell biology found in high concentrations in hepatocytes kidney adrenal cortex corpus luteum muscle modified SER = sarcoplasmic reticulum stores and releases calcium to mediate muscle contraction