Cell wall for higher growth rates in diatoms. In brown algae, phlorotannins may be a constituent of the cell walls. The group Oomycetes, also known as water molds, are saprotrophic plant pathogens like fungi. Until recently they were widely believed to be fungi, but structural and molecular evidence has led to their reclassification as heterokonts, related to autotrophic brown algae and diatoms. Unlike fungi, oomycetes typically possess cell walls of cellulose and glucans rather than chitin, although some genera (such as "Achlya" and "Saprolegnia") do have chitin in their walls. The fraction of cellulose in the walls is no more than 4
Glucose 6-phosphate precursors of DNA for growth and synthesis, G6P will also be dehydrogenated and enter the pentose phosphate pathway. If the cell needs energy or carbon skeletons for synthesis, then glucose 6-phosphate is targeted for glycolysis. Glucose 6-phosphate is first isomerized to fructose 6-phosphate by phosphoglucose isomerase. This reaction converts glucose 6-phosphate to fructose 6-phosphate in preparation for phosphorylation to fructose-1,6-bisphosphate. The addition of the 2nd phosphoryl group to produce fructose-1,6-bisphosphate is an irreversible step, and so is used to irreversibly target the glucose 6-phosphate breakdown to provide energy for ATP production via glycolysis. If blood glucose levels are high, the