NFS 2030 Chapter 6

Nitrogen

The unique chemical element found in proteins that is absent in carbohydrates and lipids.

Amine Group

Nitrogen-containing structure (-NH2) of an amino acid backbone that is converted to urea upon breakdown.

Peptide Bond

Chemical bond formed between the amine group of one amino acid and the acid group of another.

Essential Amino Acids

The 9 amino acids that the body cannot produce and must be obtained through food.

The 9 Essential AAs

Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine.

Denaturation

Irreversible change in a protein's 3D shape caused by heat, acid, alcohol, bases, or heavy metal salts.

Stomach HCl

Hydrochloric acid that denatures dietary proteins and activates pepsin in the stomach.

Ribosomes

Cellular protein-making machinery where mRNA and tRNA synthesize amino acid chains.

Protein Adult RDA

0.8 grams per kilogram of body weight per day.

Protein AMDR

10% to 35% of total daily calories.

Positive Nitrogen Balance

Nitrogen intake exceeds output; occurs during growth, pregnancy, and muscle building.

Negative Nitrogen Balance

Nitrogen output exceeds intake; occurs during starvation, trauma, severe burns, and bedrest.

Complete Protein

Protein containing all 9 essential amino acids in adequate amounts (animal proteins, soy, quinoa).

Limiting Amino Acid

The essential amino acid in shortest supply in a food protein, halting body protein synthesis.

Complementary Proteins

Two plant protein foods combined (e.g., grains + legumes) to supply all 9 essential amino acids.

Urea

Nitrogen waste product produced by the liver from excess amino acid amine groups and excreted by kidneys.

Celiac Disease

Autoimmune response to gluten protein damaging small intestine villi; requires strict gluten-free diet.

Single Amino Acid Supplements

Not recommended because oversupplying one amino acid blocks intestinal absorption sites for others.

Vegan Diet

Strict plant-based diet excluding all animal-derived foods (meat, dairy, eggs, honey).

Lacto-Ovo Vegetarian

Vegetarian diet including dairy and eggs but excluding meat, poultry, and fish.

Nutrients Deficient in Vegans

Vitamin B12, Vitamin D, Calcium, Iron, Zinc, and Omega-3 fatty acids.