Overview Nitrogen balance positive amino acid (AA) intake > excretion examples growth pregnancy negative AA excretion > intake examples kwashiorkor starvation infection AA absorption in intestine proteins degraded by trypsin and pepsin enteropeptidase cleaves trypsinogen (inactive) to trypsin (active) absorbed as AA's across the gut lumen with specific transporter for similar AA's e.g., transporter for basic AA's, transporter for large neutral AA's deficiencies lack of absorption with pancreatitis due to ↓ in degradative enzyme production Hartnup disease defect in large neutral AA transporter in the intestine and renal proximal tubule cells result is a tryptophan deficiency presents similar to pellagra AA absorption in kidney AA's that are filtered from the glomerulus can be actively reabsorbed in the proximal convoluted tubules with similar transporters as the gut deficiencies cystinuria genetic defect in transporter for cysteine, ornithine, lysine, arginine AR presentation cystine staghorn calculi note: cystine = 2x cysteine attached by a disulfide bridge cystine kidney stones result from high concentrations in urine treatment alkalinization of the urine with acetazolamide
QUESTIONS 1 of 2 1 2 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.BC.15.74) A 12-year-old boy presents to the pediatrician for the dermatological changes seen in Figure A that began two weeks ago after he begun his first day of football practice. The skin eruptions appeared to be localized solely to sun exposed areas. The boy notes that he has also had diarrhea, headaches, and confusion appearing at the same time. On examination, the pediatrician notes ataxia and tremors in the boy. A urinalysis revealed elevated levels of tyrosine, leucine, valine, isoleucine, tryptophan, glycine, alanine, and phenylalanine. Which of the following vitamin deficiencies would produce a similar clinical presentation? QID: 106622 FIGURES: A Type & Select Correct Answer 1 Thiamine 13% (50/372) 2 Riboflavin 1% (5/372) 3 Niacin 68% (252/372) 4 Pyridoxine 13% (47/372) 5 Cobalamin 3% (13/372) M 1 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic
All Videos (0) Biochemistry | Amino Acid Absorption Biochemistry - Amino Acid Absorption Listen Now 10:58 min 11/26/2022 8 plays 0.0 (0)