E.R., The golgi Body And Vesicles

E.R., Golgi And Vesicles E.R. And Vesicles Thousands of structures with membranes crowd the eukaryotic cytoplasm, the most numerous being called the endoplasmic reticulum (ER), a dense network of membranes running through the cytoplasm of every cell and enclosing a network of interconnected tubes (cisternae), which form a connecting channel throughout the cytoplasm. ‘Endoplasmic’ means ‘inside the cytoplasm’, and ‘reticulum’ means ‘network’. The E.R. can make up a significant percentage of the …

…destination of its freight with the help of carbohydrate markers, which act as labels. For example, adding the sugar mannose-6-phosphate to a protein will ensure that it is sent to a particular organelle called a lysosome. Other sugars may direct a Golgi product elsewhere, such as the cell membrane. Most targeting is not, in fact, by sugars but by "signal sequences" in the protein chain. This form of intracellular labelling is called "protein targeting".