AAMC FL 4 BB question with complete solution 2023

AAMC FL 4 BB question with complete solution 2023Most cytochrome P450 enzymes alter the activity of drugs by: A. phosphorylating them. B. dephosphorylating them. C. oxidizing them. D. reducing them. cytochrome is found in ETC, which is known for oxidative phosphorylation! cytochrome is known to accept electrons therefore they are oxidizing agents phosphorylation part is for the ATPase so not that oxidation is the correct answer cytochrome An iron-containing protein, a component of electron transport chains in mitochondria and chloroplasts oxidizing agent During phosphorylation of STAT5b proteins, phosphate groups are exchanged for what atoms on tyrosine residues? A. Hydrogen atoms of hydroxyl groups B. Hydrogen atoms of methyl groups C. Oxygen atoms of hydroxyl groups D. Carbon atoms of methyl groups phosphorylation effects the OH group they want the hydrogen on the hydroxyl group! so A phosphorylation effects OH group of the amino acid where the H is exchanged Given that antibiotics like erythromycin are metabolized by estrogen-sensitive P450 enzymes within the liver, which graph best predicts the expected relative half-life of erythromycin in adult males versus adult females? Passage: "erythromycin are metabolized by estrogen-sensitive P450 enzymes within the liver" Female rats, GH secretion is more frequent -> high GH presence in circulation erythyomycin are metabolized by estrogen sensitive p450 enzymes p450 genes are regulated by continuous GH females have more GH secretion P450 regulated by continuous GH erythyomycin are metabolized by 940 therefore we expect female to have lower erythyomycin half life compared to males because they have continuous GH secretion that is metabolized by P450 A defining characteristic of proteins that act as transcription factors (such as STAT5b) is that they: A. can dimerize. B. can phosphorylate other proteins. C. contain a DNA binding domain. D. are present within the nucleus of the cell. transcription factors influence transcription C! Transcription factors: have DNA binding domain that allows it to bind to regulatory nucleic acid sequences in a gene to alter transcription Based on the passage, ACC2 is most likely compartmentalized to: A. the mitochondria. B. the cell membrane. C. the cytosol. D. the lysosome. ACC2 uses acetyl coa, found in TCA which occurs in mitochondria fatty acid oxidation occurs in mitochondria Based on the passage, as compared to a wild-type mouse, an Acc2–/–/Cpt1–/– double knockout mouse is most likely to exhibit: A. increased insulin secretion. B. decreased fatty acid oxidation. C. decreased triglyceride synthesis. D. increased malonyl-CoA production. Passage: ACC2 regulate fatty acid synthesis and fatty acid oxidation, respectively, through the conversion of acetyl-CoA to malonyl-CoA KO = for fatty oxidation gene = no fatty acid oxidation ACC2 = codes for insulin resistance = yes fatty acid oxidation ACC2 (-) = no insulin resistance = no fatty acid oxidation IF THERE IS NO ACC2 THERE IS NO FATTY ACIS SYNTHESIS/OXIDATION B!!! decreased fatty acid oxidation During the ACC1- or ACC2-catalyzed formation of malonyl-CoA, what is the structure of the functional group added to acetyl-CoA? Passage: "The acetyl-CoA carboxylases ACC1 and ACC2" expecting a carboxyl group on acc1/acc2 so C! The researchers want to generate a mutant mouse strain that expresses a constantly active variant of ACC2 by replacing the amino acid at position 212 with a different residue. Which residue is the best choice as a replacement? A. Tyrosine B. Serine