PROTEIN - Lecture Outline Proteins and Amino Acids...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Proteins and Amino Acids 9/26/11 and 9/28/11 S.E. Fleming Recommended readings: Lecture Outline Introduction Protein digestion and absorption Protein functions Quality of dietary protein Protein requirements Dietary deficiency and excess Metabolic interplay among the macronutrients Summary 2 3 Protein in the U.S. Diet Protein deficiency is rare in the United States. In the US, about two-thirds of dietary protein comes from meat, poultry, seafood, eggs and dairy products. Most of the world relies on plant proteins from grains and vegetables. As a country’s economy improves, the proportion of animal foods in the diet tends to increase. Proteins are comprised of many amino acids 4 Each amino acid contains carbon, hydrogen, Peptide Bonds - Needed to make a protein from amino acids 5 Proteins may contain anywhere from 50 to 2000 amino acid residues. Protein Structure: Configuration = Function 6
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 7 If Protein Shape is Altered, Function May Be Altered 8 Essential Amino Acids Amino acids are the building blocks of protein. Every protein contains some “essential” amino acids. Essential amino acids cannot be synthesized by the human body in sufficient amounts to meet needs. Essential amino acids must be provided by the diet. 9 Amino Acids 10 Transamination reactions Some non-essential amino acids can be made in the body by the process of transamination. Lecture Outline Introduction Protein digestion and absorption Protein functions Quality of dietary protein Protein requirements Dietary deficiency and excess Metabolic interplay among the macronutrients Summary 11 12 Protein Digestion and Absorption
Background image of page 2
3 Protein Digestion in the Stomach Proteins denatured by HCl Pepsin breaks protein amino acids Chemicals needed for digestion: 1. Gastrin stimulates synthesis of HCl and pepsinogen 2. Pepsin formed from proenzyme Pepsinogen pepsin 13 Protein Digestion in the Small Intestine Peptidases from intestine & pancreas break peptides amino acids Amino acids taken into intestinal
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 8

PROTEIN - Lecture Outline Proteins and Amino Acids...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online