Healthy cartilage (found in our joints) is composed of a macromolecule called chondroitin and has the amino acid glucosamine making up a large component. For people with joint damage, glucosamine and chondroitin are two dietary supplements that may help rebuild damaged cartilage. Yet there is some controversy: Both of these molecules have absorption rates less than 35% and may be relatively expensive. Glucosamine has a molecular weight (this basically tells us the mass of all the protons and neutrons making up the molecule and gives us an idea of how big the molecule is) of about 216 g/mol while chondroitin has a molecular weight of about 463 g/mol. By contrast, water has a molecular weight of 18 g/mol. Another way to say this is that glucosamine and chondroitin molecules are about 12 and 26 times larger, respectively, than water molecules!

You did experiments this week with diffusion. Based on what you learned and the above information, what could explain the controversy of glucosamine and chondroitin dietary supplements?