RIBOSOMES - or to the plasma membrane for export from the...

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RIBOSOMES-  some are attached to rough ER, others are free in cytoplasm. Their function is  protein synthesis. Eukaryotic ribosomes are slightly different from those of prokaryocytes.  Eukaryocytes have 80 S ribosomes, with one 60 S and one 40 S subunit. The subunits are made  in the nucleolus and leave the nucleus separately. They join in the cytoplasm.  a. Free ribosomes--free in cytoplasm, synthesize proteins used inside the cell. b. Membrane-bound ribosomes--attached to rough ER , synthesize proteins which will: 1) Leave the cell 2) Be inserted into the plasma membrane 3) Become the enzymes in lysosomes Sometimes 10 - 20 ribosomes may join in a string--this is called a polyribosome.  GOLGI COMPLEX - consists of several flattened sacs called cisterns, stacked on top of each  other. The ends of the cisterns can detach to form vesicles to transport substances within the cell 
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Unformatted text preview: or to the plasma membrane for export from the cell. The Golgi complex receives proteins and lipids from the ER and then sorts, packages, and delivers them. a. These proteins and lipids may become part of the plasma membrane b. Enzymes may be placed in vesicles to form lysosomes. c. Proteins may be sent out of the cell by exocytosis. LYSOSOMES- vesicles formed in the Golgi complex containing digestive enzymes. These can break down most organic molecules, including bacteria taken into cells by phagocytosis. VACUOLES-spaces or cavities inside a cell, enclosed by a membrane called a tonoplast. a. Some temporarily store proteins, sugars, organic acids, and ions. b. Form during endocytosis to bring food into the cell. c. Some contain waste and toxins. d. May take up water, making plant leaves and stems rigid....
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