Chapter 15, Problem 15.21EP

(a)

Interpretation Introduction

Interpretation: To identify whether lysine can or cannot be synthesized in the body in amounts adequate to meet the body’s needs.

Concept introduction: Amino acids are the main building blocks of proteins. Amino acids are classified as essential and non-essential depending upon whether they can be synthesized within the body itself or not.

Essential amino acids are those amino acids which cannot be synthesized by the body via biosynthesis and thus must be taken from the outside in form of dietary protein to meet the body’s need. Those amino acids which can be synthesized by biosynthesis within the liver are termed as non-essential amino acids.

The essential amino acids are arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

The non-essential amino acids are alanine, asparagines, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.

(b)

Interpretation Introduction

Interpretation: To identify whether cysteine can or cannot be synthesized in the body in amounts adequate to meet the body’s needs.

Concept introduction: Amino acids are the main building blocks of proteins. Amino acids are classified as essential and non-essential depending upon whether they can be synthesized within the body itself or not.

Essential amino acids are those amino acids which cannot be synthesized by the body via biosynthesis and thus must be taken from the outside in form of dietary protein to meet the body’s need. Those amino acids which can be synthesized by biosynthesis within the liver are termed as non-essential amino acids.

The essential amino acids are arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

The non-essential amino acids are alanine, asparagines, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.

(c)

Interpretation Introduction

Interpretation: To identify whether serine can or cannot be synthesized in the body in amounts adequate to meet the body’s needs.

Concept introduction: Amino acids are the main building blocks of proteins. Amino acids are classified as essential and non-essential depending upon whether they can be synthesized within the body itself or not.

Essential amino acids are those amino acids which cannot be synthesized by the body via biosynthesis and thus must be taken from the outside in form of dietary protein to meet the body’s need. Those amino acids which can be synthesized by biosynthesis within the liver are termed as non-essential amino acids.

The essential amino acids are arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

The non-essential amino acids are alanine, asparagines, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.

(d)

Interpretation Introduction

Interpretation: To identify whether tryptophan can or cannot be synthesized in the body in amounts adequate to meet the body’s needs.

Concept introduction: Amino acids are the main building blocks of proteins. Amino acids are classified as essential and non-essential depending upon whether they can be synthesized within the body itself or not.

Essential amino acids are those amino acids which cannot be synthesized by the body via biosynthesis and thus must be taken from the outside in form of dietary protein to meet the body’s need. Those amino acids which can be synthesized by biosynthesis within the liver are termed as non-essential amino acids.

The essential amino acids are arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

The non-essential amino acids are alanine, asparagines, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.