If i'm not mistaken amino acids can be used in our body to fuel a process in which cell replication occurs and DNA is made. So to use amino acids as fuel you would have to make sure everything is in correct order and lines up correctly from the time it's released from the nucleus to a ribosome.
The relationship between the bone and muscle
I would pick younger and thinner, but follow your gut because I really don't know
Answer:
Energy ---> Force ---> Motion
Explanation:
Energy is required in order to apply force, and force is require in order for movement to take place