Module 7: Figure white fat cells

The functional organization of white fat cells.

The white fat cells are tightly packed to form a compact tissue with a sparse blood supply. Each cell contains a large lipid droplet, which can displace the cytoplasm to the periphery, where it forms a thin ring containing mitochondria and some smaller lipid droplets with a consistency resembling that of the large droplet. A conventional membrane does not surround the lipid droplet, but there is a structural web at the surface mainly composed of a protein called perilipin, which appears to provide a structural framework for organizing the enzymes that control lipid deposition and mobilization. ACTH, adrenocorticotrophic hormone; NE, noradrenaline (norepinephrine).