PROTEINS PI Functions o Growth and maintenance o Enzymes o Hormones o Fluid balance o Acid base balance o Transportation o Antibodies o Energy Proteins are not stored and therefore are not used as the body s primary energy source 20 AA with different side chains o GLY Glycine Aliphatic o ALA Alanine Aliphatic o VAL Valine Aliphatic o LEU Leucine Aliphatic o ILE Isoleucine Aliphatic o SER Serine OH group o THR Threonine OH group o CYS Cysteine Sulfur group o MET Methionine Sulfur group Aliphatic o PRO Proline Imine group o PHE Phenylalanine Aromatic group o TYR Tyrosine Aromatic group o TRP Tryptophan Aromatic group o ASP Aspartate or Aspartic Acid Acidic Carboxylic group o GLU Glutamate or Glutamic Acid Acidic Carboxylic group o ASN Asparagine Carboxylic group o GLN Glutamine Carboxylic group o HIS Histidine Basic group o LYS Lysine Basic group o ARG Arginine Basic group Dietary protein o Exogenous Outside the body what you eat Quality Digestibility o Animal proteins 90 99 o Plant sources 70 90 High fiber concentration which reduces digestibility and absorption in humans AA composition Trick Essential AAs are essential for me to eat o Complete Proteins There are 9 essential AAs which humans cannot auto synthesize Contains all essential AAs therefore we must consume them HIS LEU LYS ILE PHE VAL MET TRP THR Missing essential AAs o Incomplete Proteins Plant sources must be combined to obtain all essential AAs o Complete proteins All animals sources Exceptions Gelatin Deficient in TRP Tryptophan Soy Complete protein but does have a MET Methionine deficiency o Trick Man Soy is deficient in sulfur MET is sulfur containing AA o Soy is unique in that it is considered a complete protein for average adult RDA Recommended Dietary Allowance o Incomplete Limiting AA AA you re missing Trick Same idea as limiting reagent in chemistry o Complementing proteins 2 or more proteins when combined provide all essential AAs Beans and Rice or Lentil Soup and Cornbread both are dank combo choices Protein requirements o EAR estimated average requirement 0 66 g kg day Lowest amount to maintain nitrogen balance of 0 in average healthy adult Based on a reference protein that is highly digestible and complete are the go to example here Eggs are the poster child of reference o RDA recommended dietary allowance Covers about 98 of the healthy US population Special Needs Genera Guidelines Memorize this table she s going to ask a specific question on the values Eggs proteins 0 8 g kg day 2 SD Patient Infants Children Adolescents Pregnancy Lactation Surgery Burns Renal Insufficiency g day 11 9 1 19 46 52 25 25 g kg day 1 2 1 5 0 95 0 85 1 1 1 1 1 2 1 4 1 6 2 0 0 6 0 8 Burn victims need a high protein diet because they are producing extreme amounts of new tissues and synthesizing antibodies to fight infections or bacteria o Decubitus Ulcers Bed sores o Clinical issues Caused by decreased movement commonly seen in patients who are confined to a bed immobile Increased protein intake is required to compensate for the increased need for skin cell synthesis BCAA Branch Chain AAs are used in supplements for patients with decreased liver function HN formulas Arginine High Nitrogen promote healing in those with low protein intake promotes wound healing plays role in collagen synthesis Trick ARG A pirate needs arginine to heal his wounds and collagen synthesis probably a good call to just memorize this one enteral formulas enter o intestine increases protective response Glutamine in the gut Trick Glut for the gut Calculating protein requirements o 1 kg 2 2 lbs memorize o 1 g protein 4 kcal memorize o 1 g protein 0 16 g N memorize o Proteins contribute 10 30 total kcal o Example A healthy adult female weighing 125 pounds consumes 50 g of protein day How many g kg is she consuming 125 lbs 2 2 lbs 56 8 kg 50g 56 8 kg 0 88g kg How many g of N is she consuming 50 g pro 0 16 g 8 g nitrogen consumed Nitrogen balance tells whether your body is in catabolic anabolic or equal state refer to N Balance How many calories does this amount of protein contribute 50 g protein 5 kcal 200 kcal If she consumes 2000 kcal what is protein 2000kcal 200kcal 10 In class 200kcal protein 2000 kcal total 100 10 o Trick Composition formula o This way makes more sense in my brain because this is the same formula we have used in Gen CHM and Orgo Take your pick Can we get too much protein o AAs urea excreted by kidney o High protein diet should be avoided if the patient has Kidney disease 1 kidney or decreased kidney functioning Patient is an Infant remember back to what she was saying about cow s milk versus breast milk Cows milk is more protein dense than breast milk Infants need protein but not as much protein as an average adult therefore switching from breast milk to cows milk is bad for the infant o Alpha keto acid from metabolized AAs and therefore proteins can be Converted to ATP Stored as fat o AA supplements 11 transporters for 20 AA Transporters in intestinal cells There s a competition for transporters Not a problem when you re consuming whole protein AA supplements limit absorption of whole proteins Some AA supplements have even been found to be toxic Pure Tryptophan is not FDA approved TRP contamination can cause Eosinophilia Myalgia and Death Protein Energy Malnutrition PEM o Kwashiorkor Eventually child will catch up and the disease will disappear Illness of 1st child when 2nd child is born Normal calories decreased protein Older infants and children but no long term effects Acute PEM Fatty liver Rapid onset Edema do not have sufficient protein concentration to make albumin which aids in osmotic pressure maintenance o Marasmus Severe deprivation Chronic PEM Decreased calorie and protein intake Muscle wasting No body fat No edema No fatty liver Protein digestion and absorption o Gastric digestion Gastrin getting ready for the food Stimulated by food or thought Stimulates HCL production HCL Produces by parietal cells Denaturation of proteins into its primary structure straight chain of AAs Convert pepsinogen zymogen inactive enzyme pepsin active enzyme o The body uses inactive enzymes called zymogens to prevent the activities of the active enzyme from occurring before they are necessary Secreted into lumen of stomach by gastric chief cells Pepsinogen Activated by HCL Pepsin Autocatalytic self activation HCL initially reacts with pepsinogen to form pepsin creating a cascade event where pepsin molecules activate other pepsinogen molecules o We
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