Protein Metabolism I

Question 1

g glutamyl carboxylase

Answer 1

glu–> gla

vitamin K dependent

Question 2

Components of collagen

Answer 2

Hyp (H- bonding) and Hyl (interchain cross links)

Question 3

Scurvy

Answer 3

vitamin c is coenzyme for production of Hyp and Hyl

Prolyl hydroxylase: Pro–> Hyp
Lysyl hydroxylase: Lys–> Hyl

Question 4

Ubiquination

Answer 4

Proteosome
ATP Dependent
cross links protein to ubiquitin
ubiquinated proteins sequestered to lysosome

Question 5

Lysosomal Pathway

Answer 5

ATP Independent
engulfs extracellular/ live pathogens
proteins broken down by acid hydrolysis and other

Question 6

Pepsin

Answer 6

stomach

cleaves HCL to produce pepsins

Question 7

Enteropeptidase

Answer 7

intestine
cleaves trypsin
activated by other proteins including trypsin

Question 8

trypsin

Answer 8

made in pancreas, goes to small intestine

cleaves all other zymogens in small intestine

Question 9

what vitamin derivative is used by aminotransferases?

Answer 9

Vitamin B6 derivative: PLP

used by transferases to add/ transfer AA

Question 10

Urea cycle

Answer 10

NH4 + Asparate + 3ATP + HCO3 –> urea + fumarate + 2ADP + 2AMP + 2Pi +2PPI

Question 11

location of urea cycle

Answer 11

mitochondria; cytosol

Question 12

what is recycled in the urea cycle?

Answer 12

ornithine

Question 13

entry points for nitrogen in urea cycle

Answer 13

aspartate, free ammonia