Biochem - UWorld

mlinnie's version from 2017-09-18 06:03

Section 1

Question Answer
argininenitric oxide (via nitric oxide synthase)
arigine + aspartate = urea
glycine + succinyl-CoA = ?heme
glycine + arginine + SAM =?creatine
glutamateGABA or glutathione
glutamate + aspartate?pyrimidines
glutamate + aspartate + glycine =?purines
tryptophanserotonin --> melatonin
Tyrosinethyroxine, melanin

Section 2

Question Answer
what marker/antibody is HIGHLY SPECIFIC for rheumatoid arthritis?antibody to citrullinated peptides/proteins
anti-citrullinated peptidesRA
anti-cyclic citrullinated antibodies (anti-CCP)rheumatoid arthritis
what recognizes complementary sequences in 16S rRNA and 30S ribosomal subunit?shine-delgarno element (which is only in PROKARYOTES)
which antibiotic inhibits peptidyltransferase during translation?chloramphenicol
whats the role of peptidyltransferase in protein synthesis?part of the 50S ribosomal subunit needed for the transfer of aa from A to P site and for formation of peptide bonds
what is translocation during translation?during elongation, ribosomes move in 5-->3' direction on mRNA = translocation
which 2 antibiotics inhibit translocation step?clindamycin and erythromycin (macrolide)
what 2 molecules does branch chain aa LEUCINE form during its catabolism?acetoacetate and acetyl-CoA
what molecule forms during catabolism of branch chained aa valine and isoleucine?succinyl-CoA
anemia associated with disfigured nail beds?iron deficiency anemia
how does TNF-alpha cause insulin resistance?activates serine kinases that causes threonine phosphorylation of insulin receptor substrates
what aa is an immediate source of nitrogen for urea in the urea cycle?aspartate and NH3
what molecules activates carbomyl phosphate synthetase I of urea cycle?N-acetylglutamate (NAG) which is produced from glutamate and acetyl-Coa
what enzymes catalyzes the first step in beta-oxidation pathway?acyl-CoA dehyrogenase

Section 3

Question Answer
foamy histiocytes seen in infantneimann picks disease (foamy histiocytes are sphingomyelin-laden histiocytes)
globoid cell leukodystrophykrabbes disease = deficiency in galactocerebroside
what type of proteins does RER make?secretory, lysosomal, and integral membrane proteins
what does SER make?steroid and phospholipids
name 3 places that contain STEROID producing cellscells in adrenals, gonads, liver
which 2 cells types CANT use ketones as an energy source?RBCs (since no mitochondria) and hepatocytes (lack succinyl-CoA acetoacetate CoA transferase)(thiophorase)
can the brain use ketones as an energy source?YUP!
which enzyme does hepatocytes lack and therefore cant use ketones as energy source?succinyl-CoA acetoacetate CoA transferase (thiophorase)
whats the tx for CO poisoning?100% oxygen
what 2 amino acids are crucial for transporting nitrogen throughout the body?alanine and glutamine
deficiency of what TCA enzyme cause riboflavin (FAD) defiiency?succinate dehydrogenase
what enzymes causes succinate --> fumarate?succinate dehydrogenase
acid-maltase deficiencypompe disease = type II glycogen storage disease

Section 4

Question Answer
which gout medication interferes with neutrophil chemotaxis?colchicine = used for acute gout attacks
which aa does not conform to alpha helical structures?proline