Portage Biochem Module 8 Q & As
(Verified Answers) 2026 Update
Carbon skeleton - Correct Answers ✅carbon portion of
amino acids, the structural framework
Portions of a protein yielding Acetyl-CoA - Correct Answers
✅Carbon atoms, also H and O
Deamination - Correct Answers ✅Removal of amine group
from an amino acid resulting in ammonium, NH4
Urea Cycle - Correct Answers ✅4-step process converting
NH4 to urea, which is then excreted from the body
Urea properties conducive to exporting Nitrogen - Correct
Answers ✅High water solubility due to H bonding; high
density of N atoms in a small molecule
Urea cycle precursor - Correct Answers ✅NH4 is converted
to carbamoyl phosphate by carbamoyl phosphate synthetase.
2 ATP are used
Urea cycle reaction 1 - Correct Answers ✅Carbamoyl
phosphate is converted to citruline by arnithine
transcarbamoylase
, Portage Biochem Module 8 Q & As
(Verified Answers) 2026 Update
Urea cycle reaction 2 - Correct Answers ✅Citruline is
converted to arginosuccinate by arginosuccinate synthetase.
ATP is converted to ADP + PPi; Aspartate is released
Urea cycle reaction 3 - Correct Answers ✅Arginosuccinate
is converted to Arginine by arginosuccinase. Fumarate is
released.
Urea cycle reaction 4 - Correct Answers ✅Arginine is
converted to ornithine by arginase. H20 is added and urea is
released.
Urea cycle reaction taking place in mitochondrial matrix -
Correct Answers ✅Reaction 1
Urea cycle reactions taking place in cytosol - Correct
Answers ✅Reactions 2-4
Citrullineamia - Correct Answers ✅Mutation to
arginosuccinate synthetase enzyme at reaction 2
Other urea cycle disorders - Correct Answers
✅Arininosuccinic aciduria, arginaemea
(Verified Answers) 2026 Update
Carbon skeleton - Correct Answers ✅carbon portion of
amino acids, the structural framework
Portions of a protein yielding Acetyl-CoA - Correct Answers
✅Carbon atoms, also H and O
Deamination - Correct Answers ✅Removal of amine group
from an amino acid resulting in ammonium, NH4
Urea Cycle - Correct Answers ✅4-step process converting
NH4 to urea, which is then excreted from the body
Urea properties conducive to exporting Nitrogen - Correct
Answers ✅High water solubility due to H bonding; high
density of N atoms in a small molecule
Urea cycle precursor - Correct Answers ✅NH4 is converted
to carbamoyl phosphate by carbamoyl phosphate synthetase.
2 ATP are used
Urea cycle reaction 1 - Correct Answers ✅Carbamoyl
phosphate is converted to citruline by arnithine
transcarbamoylase
, Portage Biochem Module 8 Q & As
(Verified Answers) 2026 Update
Urea cycle reaction 2 - Correct Answers ✅Citruline is
converted to arginosuccinate by arginosuccinate synthetase.
ATP is converted to ADP + PPi; Aspartate is released
Urea cycle reaction 3 - Correct Answers ✅Arginosuccinate
is converted to Arginine by arginosuccinase. Fumarate is
released.
Urea cycle reaction 4 - Correct Answers ✅Arginine is
converted to ornithine by arginase. H20 is added and urea is
released.
Urea cycle reaction taking place in mitochondrial matrix -
Correct Answers ✅Reaction 1
Urea cycle reactions taking place in cytosol - Correct
Answers ✅Reactions 2-4
Citrullineamia - Correct Answers ✅Mutation to
arginosuccinate synthetase enzyme at reaction 2
Other urea cycle disorders - Correct Answers
✅Arininosuccinic aciduria, arginaemea
