Science Assessment

Human fingernails are made mostly of the protein keratin. Imagine your friend is complaining about her fingernails breaking all the time. She says she thinks she needs to eat more keratin in order to make her nails stronger. Do you agree or disagree? Why or why not?

1. Yes, she must eat food that is made up of keratin because the keratin from food will be added to her nails.
2. Yes, she must eat keratin because her body can only use the digestion products of keratin from food to make the keratin proteins that are needed to build new nails.
3. No, she can eat food containing proteins that can provide all the necessary building blocks (amino acids) because her body can carry out chemical reactions to change the proteins from food into the keratin proteins needed to produce new nails.
4. No, it does not matter what the food is made up of because her body can use any food as a source of energy to make the keratin proteins needed to produce new nails.