what are Structural parts of the body such as skin and hair are made of?

Question

anonymous · Answer

There is one particular protein (or family of proteins, I guess) that plays a key structural role in both skin and hair... it begins with K. Can you guess what it might be?

anonymous · Answer

keratin

blues · Answer

Calliope and Phascolarctos are right: both hair and skin contain many cells which are full of keratin. That said, they have more differences than similarities: the hair cells are all dead whereas the skin cells in the bottom layers of the epidermis are still alive. Also, the dead hair cells are much more strongly attached to each other than skin cells which slough off after they die and are replaced continuously.