1. Lecture 6b-10 February 2016 Most of this lecture taken from Chapters 6,7 of Rolfes et al(Understanding Normal and Clinical Nutrition (Nutrition 2104/2106 text)

2. Lecture 6b-10 February 2016 Protein metabolism and regulation

3. Outline of lectures 6a,b Amino acids Definition of amino acid Structure of amino acid Non-essential amino acids Essential amino acids Conditionally essential amino acids Class exercise

4. Outline of lectures 6a,b Proteins Definition of protein Amino acid chains Amino acid sequence Protein shapes Protein functions Protein denaturation Digestion Absorption Transport

5. Outline of lectures 6a,b Metabolism Amino acid anabolism Protein anabolism Protein catabolism Amino acid catabolism Nitrogen balance Regulation of amino acid and protein metabolism

6. More detailed comments

7. Proteins Absorption -specific carriers move amino acids and a few dipeptides and tripeptides into intestinal cells -once inside intestinal cells amino acids can be used for energy or to synthesise some proteins

8. Proteins Transport -rest of amino acids put directly into blood and taken to liver -are amino acid carriers required for free amino acids to transport those free amino acids in the blood?

9. Proteins Class exercise -what happens to protein functions if there are insufficient: a) essential amino acids in the diet? why? b) non-essential amino acids in the diet? Explain -what happens to protein functions if there are sufficient? c) essential amino acids in the diet? explain

10. Metabolism Protein anabolism amino acids joined to amino acids figure 6-7 Rolfes et al

11. Fig. 6-7, p. 188

13. Metabolism Protein catabolism -digestion in stomach and small intestine -non gi tract catabolism

14. Metabolism Amino acid catabolism -figure 7-13 Rolfes -figure 7.24 Gropper - get urea which is excreted in urine

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17. Metabolism Nitrogen balance -equilibrium N in = N out healthy adult -negative nitrogen balance N in < N out illness, starvation -positive nitrogen balance N in > N out -person recovering from illness -growing child

18. Regulation of amino acid and protein metabolism -demand for amino acid and protein anabolism -eg if need positive N balance or to keep in N equilibrium -if lots of glucose available -demand for amino acid and protein catabolism-eg if in negative N balance or to keep in N equilibrium -if short of glucose

19. Relation of protein metabolism to carbohydrate and lipid metabolism -figure 7-8 Rolfes et al.

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21. Class exercise Explain the importance of dietary carbohydrate to protein metabolism Explain the importance of dietary lipid to protein metabolism Explain the importance of dietary protein to protein metabolism