glyoxysomlarda

Glyoxysomes are specialized peroxisomes found in plants and fungi, and in some bacteria. They are involved in a metabolic pathway called the glyoxylate cycle, which is a modified version of the citric acid cycle. This cycle allows plants to convert stored fatty acids into carbohydrates during seed germination, a process crucial for providing energy to the developing seedling before it can photosynthesize.

In glyoxysomes, fatty acids are broken down through beta-oxidation. The resulting acetyl-CoA molecules then enter the glyoxylate cycle. Unlike the citric acid cycle in animals, the glyoxylate cycle bypasses the steps that release carbon dioxide, thus allowing the net synthesis of four-carbon dicarboxylic acids, such as oxaloacetate. These dicarboxylic acids can then be used in gluconeogenesis to produce glucose.

The glyoxylate cycle is primarily active during the early stages of seed germination when the plant relies on stored lipids for energy. Once the seedling develops photosynthetic capacity, the glyoxysomes typically disappear or their function is taken over by other peroxisomes. The presence and activity of glyoxysomes are tightly regulated by developmental and environmental cues. Their discovery and elucidation of the glyoxylate cycle have been fundamental to understanding plant metabolism and energy storage.