Protein #2

• Protein


  An essential part of the human diet, found in a variety of foods like eggs, dairy, seafood, legumes, meats, nuts and seeds
• Protein breakdown and reformation


  Protein from food gets broken down into individual amino acids, which are then reformed into new proteins in the body
• Amino acid


  A chain of amino acids bound together by peptide bonds, with a central carbon atom, one amino or nitrogen-containing group, one carboxylic acid group, and a unique sidechain
• Non-essential amino acids


  Amino acids that the body can make itself (alanine, asparagine, aspartic acid, glutamic acid, serine)
• Conditionally essential amino acids

  Amino acids that the body can normally make, but may need to be obtained from food in certain circumstances (arginine, cysteine, glutamine, glycine, proline, tyrosine)
• Essential amino acids


  Amino acids that can only be obtained from food (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine)
• Protein digestion


  Hydrochloric acid denatures the protein, making it more accessible to pepsin, which cleaves the protein into smaller oligopeptide chains; these are further broken down into tripeptides, dipeptides, and individual amino acids in the duodenum
• Protein sources


  Animal-based foods (eggs, dairy, seafood, meat) provide all 9 essential amino acids; plant-based foods (soy, whole grains, legumes, nuts, seeds) may be lower in some essential amino acids but can provide all 9 when a variety is consumed
• A cup of tofu has the same amount of protein as 3 ounces of steak, chicken, or fish, and half a cup of lentils has more protein than an egg
• Protein requirements


  Based on studies estimating the minimum amount to avoid nitrogen loss; generally 0.8 g/kg body weight for healthy adults, with variations by age, sex, and health status
• Certain individuals may be at risk for protein deficiency, including those with malnutrition, trauma, burn injuries, and conditions impacting nutrient absorption
• Except for certain conditions like kidney disease, there is usually no health risk associated with eating a lot of protein, as the body can process it