And to begin in this lecture, we're going to focus on disaccharides. Now, generally speaking, what exactly is a disaccharide? Well, a disaccharide is a carbohydrate that consists of two individual monosaccharides which are connected by a special type of linkage, a special type of bond we call the Oglycocitic bond, which we introduced in the previous lecture. Now, to demonstrate what types of disaccharides we can have and the types of Oglycocitic bonds that we can have in nature, let's take a look at the three most common types of disaccharide. So, these are maltose, lactose, and sucrose. So let's begin with maltose.