Simplified triacylglycerol and starch metabolism in green microalgae. Not all reactions are shown, and the cofactors upstream of 3PG are not considered. The dashed lines are reactions that take place in the cytosol. From 28 molecules of 3PG, one molecule of C18 TAG can be formed or 14 molecules of glucose in a starch matrix. Two possible ways for the formation of TAG molecules are shown following the postulated route in the chloroplasts or over the ER membranes in the cytosol[17–19]. 3PG, 3-phosphoglycerate; ER, endoplasmic reticulum; TAG, triacylglycerol.