And this phospholipid bilayer is more permeable than our inner plasma membrane. So it actually allows relatively large molecules to pass through that phospholipid bilayer, for example, it allows sugar molecules to pass right through. And the sugar molecules, because the actual wall contains pores, will end up within this section. And then those sugar molecules can either be broken down by the hydrolytic enzymes or they can be ingested directly into our cell wall. Now, another difference between our Gram negative and Gram positive is because our Gram negative contains this second phospholipid bilayer. That phospholipid bilayer contains special types of molecules known as lipopolysaccharides.