PRESENTATION OUTLINE
There are two basic types of ER. Both rough ER and smooth ER have the same types of membranes but they have different shapes. Rough ER looks like sheets or disks of bumpy membranes while smooth ER looks more like tubes. RoughER is called rough because it has ribosomes attached to its surface.
Rough ER (RER) is very important in the synthesis and packaging of proteins. Ribosomes are attached to the membrane of the ER, making it “rough.” The it is attached to the nuclear envelope surrounding the nucleus. This direct connection between the perinuclear space and the lumen of the ER allows for the movement of molecules through both membranes
The process of protein synthesis starts when mRNA moves from the nucleus to a ribosome on the surface of the RER. As the ribosome builds the amino acid chain, the chain is pushed into the cisternal space of the RER. When complete the proteins collect and the RER pinches off a vesicle. That vesicle can move to the cell membrane or the Golgi apparatus. Some of the proteins are used in the cell and some will be sent out into intercellular space.
