###### Smooth endoplasmic reticulum
The smooth endoplasmic reticulum (see Fig. 1.4) is associated with
carbohydrate metabolism and many other metabolic processes, including detoxification and synthesis of lipids, cholesterol and steroids. The
membranes of the smooth endoplasmic reticulum serve as surfaces for
the attachment of many enzyme systems, e.g. the enzyme cytochrome
P450, which is involved in important detoxification mechanisms and
is thus accessible to its substrates, which are generally lipophilic. The
membranes also cooperate with the rough endoplasmic reticulum
and the Golgi apparatus to synthesize new membranes; the protein,
carbohydrate and lipid components are added in different structural
compartments. The smooth endoplasmic reticulum in hepatocytes contains the enzyme glucose-6-phosphatase, which converts glucose-6phosphate to glucose, a step in gluconeogenesis.