NBCE - PART 1 / BIOCHEMISTRY - IRENE GOLD REVIEW ACTUAL 2025/2026 QUESTIONS AND 100% CORRECT ANSWERS

NBCE - PART 1 / BIOCHEMISTRY - IRENE GOLD REVIEW ACTUAL 2025/2026 QUESTIONS AND 100% CORRECT ANSWERS All amino acids are L-form except? - Answer -glycine T/F - All amino acids are amphoteric? - Answer -T What does amphoteric mean? - Answer -Can act as either an acid or a base What are the essential amino acids? - Answer -P = phenylalanine V = valine T = tryptophan T = threonine I = isoleucine M = methionine H = histidine A = arginine L = leucineL = lycine T/F - histidine is essential in a child but not an adult? - Answer -True What are the purely ketogenic amino acids? - Answer -Leucine and Lysine What amino acid is the precursor for carnitine? - Answer -Lysine What is the function of carnitine? - Answer -takes FA into mitochondria for beta-oxidation What are the aromatic amino acids? - Answer -phenylalanine tyrosine tryptophan What is unique about tryptophan? - Answer -It has an indole ring What are the sulfur-containing amino acids? - Answer -cysteine, methionine, and cystine 2 cysteines linked together make what? - Answer -cysteine What are the branched chain amino acids? - Answer -isoleucine, leucine and valine Maple syrup urine disease is a defect in? - Answer -the bodies ability to breakdown branched chain amino acids What are the acidic amino acids? - Answer -aspartate and glutamate What does aspartame contain that makes it neurotoxic in excess? - Answer -aspartic acid (aspartate) What are the basic amino acids? - Answer -histidine, lysine and arginineT/F - basic amino acids have the smallest positive net charge at NORMAL pH of blood? - Answer -F - greatest positive net charge Wheat is lacking in which aa? - Answer -lysine Rice is lacking in which aa? - Answer -lysine Legumes are lacking in which aa? - Answer -tryptophan Maize is lacking in which aa's? - Answer -lysine and tryptophan Pulses are lacking in what aa? - Answer -Methionine (or cysteine) Eggs and chicken are lacking in what aa? - Answer -none Phenylketonuria is a deficiency in which enzyme and limits conversion of which two amino acids? - Answer -Phenylalanine hydroxylase; cannot convert phenylalanine to tyrosine Tyrosine is the precursor for what neurotransmitters? - Answer -L-dopa --> dopamine --> norepinephrine --> epinephrine (catecholamines) Tyrosine is a precursor for what pigment? - Answer -L-dopa --> melanin (skin pigmentation) Albinism is a problem with the conversion of what? - Answer -L-dopa --> melanin What hormones can tyrosine be converted to? - Answer -T3, T4 What is melatonin derived from? - Answer -Tryptophan --> serotonin --> melatonin What is histamine derived from? - Answer -Histidine