Learning Exercise #27
Human muscle contains some of the same amino acids that were in the protein of the
plants that the human ate.
Explain the difference between:
Complete (higher quality) protein
Incomplete (lower quality) protein, in food
Which are the highest quality protein?
Human mother’s milk (for humans)
Next best: chicken eggs
Next: cow’s milk
Supplies all necessary amino acids
Which are the lowest quality?
Fruits and vegetables (particularly fruits)
Beans and legumes
Measure of Protein Quality
Biological value – percent of food protein (amino acids) absorbed that is retained in the
human body (metabolized into tissue)
Human milk 98%
Chicken eggs 94% Cow’s milk 85%
Red meat 76%
Poultry meat 75%
In terms of “essential amino acids”, explain what is meant by: “complementary proteins”
and give an example.
All incomplete protein sources by themselves
Complement grains with legumes
Or seeds/nuts with legumes
Intake all essential amino acids
Grains and seeds/nuts cannot be compleme