Why is celecoxib selective for COX-2 inhibition as compared to COX-1 inhibition?
COX-1 contains Ile-523, whereas COX-2 contains Val-523, which permits celecoxib binding.
COX-1 contains Ile-523, whereas COX-2 contains Val-523, which blocks celecoxib binding.
COX-1 contains Val-523, whereas COX-2 contains Ile-523, which permits celecoxib binding.
COX-1 contains Val-523, whereas COX-2 contains Ile-523, which blocks celecoxib binding.
COX-2 is located in the endoplasmic reticulum where celecoxib is active, whereas COX-1 is
located in the cytoplasm. correct answers COX-1 contains Ile-523, whereas COX-2 contains Val-
523, which permits celecoxib binding.
What controls the bioavailability of arachidonate in the eicosanoid signaling pathway?
GPCR activation of phospholipase A2 leads to cleavage of membrane lipids to produce
arachidonate.
Fatty acid synthase generates arachidonate from palmitate in a reaction requiring NADPH.
Phospholipase A2 cleaves generates prostaglandins by activating arachidonate synthase.
Arachidonate is a polyunsaturated fat derived from the diet and is found in high levels in salmon.
Release of arachidonate from adipose tissue is stimulated by the enzyme hormone-sensitive
lipase. correct answers GPCR activation of phospholipase A2 leads to cleavage of membrane
lipids to produce arachidonate.
Prostaglandins produced by COX-1 are responsible for _________ (1), whereas prostaglandins
produced by the COX-2 enzyme are responsible for ______________(2).
(1) stimulating mucin production
(2) swelling, pain, and fever
(1) stimulating mucin production
(2) causing inflammation in the joints
(1) reducing secretion of HCl in the stomach
(2) causing inflammation in the joints
(1) reducing secretion of HCl in the stomach
(2) swelling, pain, and fever
(1) swelling, pain, and fever
(2) stimulating mucin production correct answers (1) stimulating mucin production
(2) swelling, pain, and fever
, What is thought to be responsible for the increased risk of cardiovascular disease caused by some
selective COX-2 inhibitors?
Activation of prostacyclin synthase, leading to increased blood clot formation.
Inhibition of prostacyclin synthase, leading to increased blood clot formation.
Increased COX-2 activity, leading to increased blood clot formation.
Decreased COX-2 activity, leading to increased blood clot formation.
Decreased COX-1 activity, leading to decreased blood thinning activity. correct answers
Inhibition of prostacyclin synthase, leading to increased blood clot formation.
The activation of glycogen phosphorylase will lead to a(n) __________ in blood glucose
concentrations and is stimulated by the hormone __________.
decrease; glucagon
increase; insulin
increase; glucagon
decrease; insulin correct answers increase; glucagon
Activated glucose units are attached to the hydroxyl of which carbon atom in the growing
glycogen chain? correct answers C-3
C-4
C-6
C-1
Order the following steps in glycogen particle synthesis. correct answers A branching enzyme
adds α-1,6 linkages
The glycogen synthase activity of glycogenin forms an α-1,4 glycosidic bond that adds UDP-
glucose to an O-linked glucose disaccharide.
The glycosyltransferase activity of glycogenin adds UDP-glucose to a tyrosine residue in
glycogenin.
Glycogen synthase uses UDP-glucose to form α-1,4 glycosidic bonds that add to the glycogenin
primer