Ribosomes
1 one set for those proteins synthesized by ribosomes that remain suspended in the cytosol, and. 2  a second set for proteins synthesized by ribosomes that are attached to the membranes of the endoplasmic reticulum (ER) forming rough endoplasmic reticulum (RER). The cytosol often comprises more than 50% of a cell's volume. Beyond providing structural support, the cytosol is the site wherein protein synthesis takes place, and the provides a home for the centrosomes and centrioles. These organelles will be discussed more with the cytoskeleton. The ribosomes do the actual translation of mRNA into proteins. These are either free ribosomes or those located on the RER (rough endoplasmic reticulum). Ribosomes: Ribosomes … are packets of RNA and protein that play a crucial role in both prokaryotic and eukaryotic cells. They are the site of protein synthesis. RER looks rough on the surface because it is studded with very small organelles called ribosomes. Ribosomes are made of RNA and protein and are the site of protein synthesis (see DNA and Genetic Code). There may be free ribosomes in the cytoplasm as well, which also are the site of protein synthesis. 1 a second set for proteins synthesized by ribosomes that are attached to the membranes of the endoplasmic reticulum (ER) forming rough endoplasmic reticulum (RER). 2  This electron micrograph (courtesy of Keith Porter) shows the RER in a bat pancreas cell. 3  The clearer areas are the lumens. Some of the proteins that are synthesized in the cytosol and incorporated into the mitochondrion are listed in Table 17-2. The largest number are transported to the matrix, but some are transported to the intermembrane space or inserted into the outer or inner membrane. The cytosol provides a home for the nucleus and organelles as well as a location for protein synthesis and other fundamental chemical reactions. Cytoskeleton. The cytoskeleton is a protein structure that maintains cell shape and helps move organelles around the cell. Ribosomes synthesizing nascent proteins in the secretory pathway 1 are directed to the (more...). Synthesis of all other nuclear-encoded proteins is completed on “free” cytosolic ribosomes, and the completed proteins are released into the cytosol.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/ProteinKinesis.html http://www.sparknotes.com/biology/cellstructure/intracellularcomponents/section1.rhtml http://www.answers.com/Q/What_organelle_in_the_cytosol_are_proteins_synthesized http://www.s-cool.co.uk/a-level/biology/cells-and-organelles/revise-it/organelles http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/ProteinKinesis.html http://www.ncbi.nlm.nih.gov/books/NBK21652/ http://www.sparknotes.com/testprep/books/sat2/biology/chapter4section3.rhtml http://www.ncbi.nlm.nih.gov/books/NBK21480/
proteins are synthesized (made) at what organelle in the cytosol