Cells are able to convert stored fat into energy. This is achieved through a process called beta oxidation, which breaks down the fatty acids within fat molecules into smaller units called acetyl-CoA. These acetyl-CoA molecules then enter the Krebs cycle, a series of reactions that produce ATP, the primary energy currency of cells.

Here's a breakdown:

1. Fat breakdown: Stored fat, mainly in the form of triglycerides, is broken down into glycerol and fatty acids.

2. Fatty acid activation: Fatty acids are activated and transported into the mitochondria, the powerhouses of the cell.

3. Beta oxidation: Fatty acids are broken down into two-carbon units of acetyl-CoA. This process releases energy in the form of ATP and reducing equivalents (NADH and FADH2).

4. Krebs cycle: Acetyl-CoA enters the Krebs cycle, a series of reactions that produce ATP, NADH, and FADH2.

5. Electron transport chain: NADH and FADH2 from the Krebs cycle donate electrons to the electron transport chain, a process that generates the majority of ATP from the breakdown of fat.

In addition to energy, cells can also convert stored fat into other molecules, including:

* Ketone bodies: These are produced when the body is in a state of starvation or when there is not enough glucose available. Ketone bodies can be used as an alternative fuel source by the brain and other tissues.

* Hormones: Some hormones, such as estrogen and testosterone, are derived from cholesterol, which is synthesized from fatty acids.

* Cellular components: Fatty acids are used to build cell membranes and other cellular structures.

Overall, stored fat is a valuable energy source for cells, and its breakdown provides the building blocks for various cellular processes.