l||is drawing of an idealized animal 
cell is based on photographs taken 
with powerful electron microscopes. 
Within the cell's membrane are such 
organelles as the mitochondria (energy 
producers), the rough endoplasmic 
reticulum (a site of protein production), 
the Golgi apparatus (a protein sorter), 
and the largest organelle, the nucleus 
(which contains the hereditary material 
DNA). In addition to these organelles, 
cells also contain an elaborate network 
of protein filaments called the cytoskele- 
ton (not shown here) fflt anchor the 
organelles, maintain the cell's shape, 
and direct intracellular traffic. 
Nucleolus 
Nucleus 
Mitochondrion 
Roi|)||ffl 
endoplasmic 
reticulum 
Ribosomes 
Cytoplasm 
Smooth 
endoplasmic 
reticulum 
Peroxisome 
Secretory 
vesicle 
Rougi^l 
endoplasmic 
reticulum 
membrane 
Nuclear 
pores 
Golgi 
apparatus 
Centrioles 
Ly soso me 
Free 
ribosomes 
4 
