Basics of Biology

Enzymes—and Proteins—at Work

Why do you need protein in your diet?

Of the twenty amino acids used by humans as building blocks for proteins, eight are essential. In other words, our bodies cannot synthesize them, nor can we survive without them. Luckily, all of the essential amino acids can be acquired by eating animal meat (complete proteins) and/or certain plant sources (complementary proteins). Combining grains, such as rice and legumes (for example, beans or peas) in the correct proportion and amount, is usually sufficient for a person’s daily requirement of protein.


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