Question

Explain why each of the following pairs are complementary proteins:

a. Coen and Peas

b. rice and soy

Short answer

( part a) Corn and peas are both good sources of protein. Corn lacks the essential amino acids tryptophan and lysine, which peas provide. Peas, on the other hand, are deficient in methionine, which corn provides. As a result, corn and peas form a complementary protein source.

(part b) Rice and soy are complementary protein sources. Rice lacks the essential amino acid lysine, which soy provides. Rice provides the essential amino acids methionine and cysteine that soy lacks. As a result, rice and soy are complementary protein sources.

Step-by-step solution

Step 1:Introduction  (part a )

Amino acids contain an amine $\left(-{\mathrm{NH}}_2\right)$and carboxylic acid$(-\mathrm{COOH})$ functional group. The a-carbon is covalently bonded to both functional groups. All proteins are constructed from amino acids. A dipeptide is formed when two amino acids undergo a reaction that results in the formation of an amide bond between the amine group of one amino acid and the carboxylic group of the other amino acid, which joins the two amino acids. Proteins are macromolecules composed of repeating subunits known as amino acids, which determine protein shape and function.

Step 2:Given data  (part a )

Only a portion of the essential amino acids are present in incomplete protein sources. To make complementary proteins, we combine two foods with incomplete proteins. All of the essential amino acids required by the body are found in complementary protein sources.

Step 3:Corn and peas are both good sources of protein    (part a )

(a) Corn and peas are both good sources of protein. Corn lacks the essential amino acids tryptophan and lysine, which peas provide. Peas, on the other hand, are deficient in methionine, which corn provides. As a result, corn and peas form a complementary protein source.

Step 4:Rice and soy are complementary protein sources.    (part b )

(b) Rice and soy are complementary protein sources. Rice lacks the essential amino acid lysine, which soy provides.

 Explanation   (part b)

Rice provides the essential amino acids methionine and cysteine that soy lacks. As a result, rice and soy are complementary protein sources.