'Ptyalin is an enzyme in this body fluid that helps break down starches'
Saliva
THE BODY HUMAN: Ptyalin is an enzyme in this body fluid that helps break down starches
Ptyalin is an enzyme in this body fluid that helps break down starches
Ptyalin is an enzyme in this body fluid that helps break down starches
THE BODY HUMAN
Saliva
THE BODY HUMAN