solutions passed
Which of the three proteins in the ubiquitin pathway is the most responsible for recognizing the
ubiquintated target protein? - correct answer ✔✔E3
When AMPK is bound by AMP and is phosphorylated at Thr172, _________ activity will
_________. - correct answer ✔✔acetyl-CoA carboxylase; decrease
Orlistat and olestra can both lead to undigested lipids in the colon, yet they do so by contrasting
mechanisms. Orlistat ________, whereas olestra ________. - correct answer ✔✔inhibits
pancreatic lipase; is a fat substitute that is not a substrate for pancreatic lipase
Nitrogen fixation and assimilation is critical for life on Earth. Which statement below best
describes how the nitrogen cycle works in the biosphere? - correct answer ✔✔Nitrogen cycling
is not limited to amino acids, it involves biological fixation, industrial fixation, and atmospheric
fixation.
Which of these three diets below is the most incomplete with regard to nutrition and why?
Diet 1: carbohydrate + lipid
Diet 2: protein + carbohydrates
Diet 3: amino acids + fatty acids - correct answer ✔✔Diet 1; because it lacks protein, which
provides 10 essential amino acids required for protein synthesis.
Why do angina patients carry nitroglycerine with them? - correct answer ✔✔it releases nitric
oxide, which stimulates vasodilation
, Diseases affecting heme biosynthesis as a result of deficiencies in the heme biosynthetic
pathway are called _________. - correct answer ✔✔porphyria
What molecule signals the endothelial cell to produce nitric oxide, and what is the enzymatic
reaction? - correct answer ✔✔acetylcholine;
L-arginine + 1.5 NADP+ + H+ + 2O2 --> citrulline + NO + 1.5 NADPH
Albinism is characterized by white skin due to a defect in the enzyme arginase (1) tyrosinase (2),
which leads to a block in the pathway needed to synthesize adrenaline (3) / melanin (4).
Animals with this condition have a(n) decreased (5) / increased (6) risk of skin cancer. The
genetic disease phenylketonuria is caused by a defect in the enzyme tyrosine (7) / phenylalanine
(8) hydroxylase, which leads to mental deficiencies caused by a decrease (9) / increase (10) of
phenylalanine derivatives that are toxic metabolites. - correct answer ✔✔2, 4, 6, 8, 10
Nitric Oxide (NO) is a soluble gas and regulator of intracellular pathways causing vasodilation.
What is the mechanism by which NO reduces blood pressure by stimulating vasodilation? -
correct answer ✔✔NO binds to guanylate cyclase to stimulate cyclic GMP production, which
leads to vasodilation.
The conversion of ribose-1-phosphate to guanosine-5'-triphosphate via the salvage pathway
would require the activity of several enzymes. Choose the answer that lists them in the order
that they would act in this pathway. - correct answer ✔✔phosphopentomutase; PRPP
synthetase; phosphoriboxyl transferase; kinase; kinase
Individuals with type 2 diabetes are often prescribed the drug, Metformin, which activates
AMPK signaling. Why would Metformin be an effective treatment for obese individuals with
type 2 diabetes? - correct answer ✔✔AMPK increases glycolytic flux and increases fatty acid
oxidation, resulting in burning of fat stores as well as increased cellular glucose uptake.
In patients with an argininosuccinase deficiency, toxic levels of ___________ lead to many
undesirable pathophysiological effects due to the buildup of nitrogen. Patients are treated with
dietary ___________, which maintains flux through the urea cycle through conversion to urea