Final answer:
Approximately 20 amino acids have been identified as important to the body's metabolism, but only 8 of them are considered indispensable (essential) amino acids.
Step-by-step explanation:
The body can synthesize 12 amino acids, but there are 8 amino acids that are considered essential and must be obtained from the diet.
These 8 amino acids are called the essential amino acids.
Infants and children have a greater need for essential amino acids due to their growing bodies.