34 
e cells in test 
‘ enzyme and take 
tide, but they are 
n the Golgi (j). and 
lerefoi 
elsewhere in the cell.) 
However, it is now known 
that a rare, fatal genetic dis- 
order called Zellweger’s 
syndrome is the result of mal- 
formed peroxisomes, 
indicating that peroxisomes 
do have a vital role in the 
healthy cell. 
The ability of peroxisomes 
to use oxygen in chemical 
reactions has led many 
scientists to conjecture that 
these organelles represent a 
relic of an attempt by the 
Golgi without enzyme 
Lysosome 
without 
enzyme 
6 6 
Golgi apparatus Tag Enzyme 
Lysosome 
t Vesicles if 
© © 
precursors of eukaryotic cells 
to “cope” with oxygen as it 
accumulated in the prehistoric 
atmosphere. Peroxisomes 
cannot, however, couple 
oxygen use with energy pro- 
duction. That ability is 
restricted to mitochondria — 
the “energy converters” of 
eukaryotic cells. 
Golgi with untagged enzyme 
Empty 
lysosome 
o ©. 
Vesicle 
leaving 
cell 
1 . 
▲ 
No '***... 
recapture 
• • • 
Untagged enzyme 
I-cell disease 
♦ 
% 
f i ' \ "■ 
v&L 
Tagged enzymes Lysosome with enzyme 
added to cells in 
test tubes 
Hurler’s syndrome 
r 
Normal cell 
