BIBC120 - Nutri&on BIBC 120 Lecture 5 Proteins...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Nutri&on BIBC 120 Lecture 5 Proteins Linda Strause, PhD Office: Muir 2268 [email protected] Protein Efficiency Ra&o •  •  •  •  •  •  •  • Used by FDA to set standards for baby food • Compares the weight gained in a growing rat aRer 10 days or more ea&ng a standard amount of protein Gram weight gain Gram protein consumed PER =Gram weight gain/Gram protein consumed Chemical Score of Protein • Ra&o of each essen&al AA in a gram of test protein to that essen&al AA in an ideal protein (egg white). • The most limi&ng AA is used for scoring that food •  Chem.Score =mg of EAA (most limi&ng) per gm of protein/mg of EAA per gm of egg white protein Biological Value • Measure protein (AA) reten&on •  BV = Nitrogen retained/Nitrogen absorbed X 100 Protein Diges&on Protein Diges&bility Corrected •  AA Score (PDCAAS) • Most widely used (on food labels) • Maximum value is 1.0 (= milk, eggs, soy protein) •  PDCAAS = Chem. Score x (~0.9 ­1.0) Range of diges&bility Essen&al and Nonessen&al AA Func&ons of Proteins • Building blocks of body components • Maintain fluid balance • Contribute to acid/base balance • Building block for hormones and enzymes • Immune func&on • Gluconeogenesis • Energy yielding High ­Protein Diets ORen associated with: • Low intake of plant foods  ­> reduced fiber and phytonutrients. • High intake of saturated fat from animal ­based foods  ­> increases risk for heart disease. • Excessive intake of red or processed meat  ­> increased risk of colon cancer. • Glycans (carbs) from red meat and milk (mammalian protein not fish or chicken) get incorporated into human glycoproteins and s&mulate inflamma&on leading to increase risk of carcinomas • Extra burden on kidneys to excrete excess urea. Limited Amino Acids Protein Metabolism Protein Metabolism Synthesis of Tyrosine Phenylalanine Tyrosine (Essen&al AA) phenylalanine hydroxyase (Nonessen&al AA) ...
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online