Hydrolysis Reactions

00:01 Then we'll move on into looking at how these come together.

00:04 Macromolecules are all stuck together with our friend the covalent bond.

00:09 What happens here is we remove a hydrogen from one end of the molecule and a hydroxide from the other end of the next molecule, the next monomer and we extract H2O and those two molecules will bind together, they now have an affinity to pair electrons with each other so because we're losing water this is called dehydration synthesis so two monomers will come together through polymerization reaction polymerization where we lose water and that creates the affinity between the two monomers to form a covalent bond and again the covalent bonds are the strongest bonds that we see.

00:57 Single, double and clearly triple the most strong bond we'll see in biology.

01:04 On the other hand, when we metabolize polymer macromolecules for example in the metabolism of say pasta, a complex carbohydrate we're going to separate the monomers from each other in a process called hydrolysis.

01:20 Hydrolysis so we're breaking apart the water molecule.

01:26 We'll put hydrogen on one end of a monomer and hydroxide group on the other end of a monomer and now they're free to separate and that covalent bond is broken between the monomers so contrasting reactions that we see are the hydrolysis reaction breaking things apart and dehydration synthesis is bringing things together.

01:52 So now that we have an understanding of how things come together, how are monomers joined together to form polymers it's the same with every class of macromolecules.

02:02 Let's take a little bit deeper into carbohydrates.

02:05 Carbohydrates are molecules that are composed of monomers or monosaccharides.

02:12 Monosaccharides are simple sugars.

02:15 They come in the form of either three carbon sugars, there's R carbon backbone that's got hydrogen associated with it.

02:23 They could come in the form of five carbon sugars.

02:26 We'll see these when we look at ribose and deoxyribose and the structure of DNA and then we could have six carbon sugars ones we are familiar with are things like glucose and fructose and galactose.

02:38 These monomers can all come together to form polymer macromolecules.

02:44 We could have disaccharides or trisaccharides but mostly we deal with disaccharides which are two sugars coming together or polysaccharides which are multiple sugar units coming together.

02:57 In the case of disaccharides, we could look at something like glucose.