Nucleotide Metabolism Flashcards
Nucleotide
Base + Pentose + Mono-/di-/triphosphate
Nucleoside
Base + Pentose
Bond Type
N-glycosidic bond
Bond type
(Phosphate) Ester bond
Examples of Pentose groups in nucleosides
- Ribose
- (2-)deoxy-ribose
Structure of Adenine
Structure of Guanine
Structure of Cytosine
Structure of Thymine
Structure of Uracil
Give the Purine bases
- Adenine
- Guanine
Give the Pyrimidine bases
- Cytosine
- Thymine
- Uracil
Uracil binds only to…
Ribose
Thymine binds only to…
Deoxyribose
Cytosine binds only to…
Ribose or Deoxyribose
Examples of purine nucleosides
- Adenosine
- Guanosine
Examples of Pyrimidine nucleosides
- Uridine
- Cytidine
- Deoxythymidine
Name the process
Purine Synthesis (De novo)
Compound A
- Name
- Structure
Glucose
Process 1
- Enzyme
- Reactions
- Hexokinase
- ATP → ADP
Compound B
- Name
- Structure
Glucose-6-phosphate
Process 2
Pentose phosphate pathway
Compound C
- Name
- Structure
Ribose-5-phosphate
Process 3
- Enzyme
- Reactions
- PRPP synthetase
- ATP → AMP
Compound D
- Name
- Structure
5-phosphoribosyl-1-pyrophosphate
(PRPP)
Process 4
- Enzyme
- Reactions
- PRPP amidotransferase
- Glutamine → Glutamate
- → P-O-P
Compound E
- Name
- Structure
5-phosphoribosyl-amine
Process 5
- Enzyme
- Reactions
- IMP Synthase
- Glycine →
- 2 x N10-formyl-FH4 → FH4
- Glutamine → Glutamate
- HCO3- → H2O
- Aspartate → Fumarate
Compound F
- Name
- Structure
Inosine monophosphate
(IMP)
Process 6
- Enzyme
- Reactions
- IMP dehydrogenase
- H2O →
- NAD+ → NADH + H+
Compound G1
- Name
- Structure
Xanthosine monophosphate
(XMP)
Process 7
- Enzyme
- Reactions
- GMP synthetase
- ATP → AMP
- Glutamine → Glutamate
Compound H1
- Name
- Structure
Guanosine monophosphate
(GMP)
Process 8
- Enzyme
- Reactions
- Nucleotide kinase
- ATP → ADP
Compound I1
- Name
Guanosine diphosphate
(GDP)
Process 9
- Enzyme
- Reactions
- Nucleotide diphosphate kinase
- ATP → ADP
Compound J1
- Name
Guanosine triphosphate
(GTP)
Process 10
- Enzyme
- Reactions
- Adenylosuccinate synthetase
- GTP → GDP
- Aspartate →
Compound G2
- Name
- Structure
Adenylosuccinate
Process 11
- Enzyme
- Reactions
- Adenylosuccinate lyase
- → Fumarate
Compound H<span>2</span>
- Name
- Structure
Adenosine monophosphate
(AMP)
Process 12
- Enzyme
- Reactions
- Nucleotide kinase
- ATP → ADP
Compound I<span>2</span>
- Name
Adenosine diphosphate
(ADP)
Process 13
- Reactions
- Substrate-level phosphorylation
- Oxidative phosphorylation
Compound J<span>2</span>
- Name
Adenosine triphosphate
(ATP)
Which reaction produces this structure?
HCO3- → H2O
Which reaction produces this structure?
Aspartate → Fumarate
Which reaction produces these structures?
N10-formyl-FH4 → FH4
Which reaction produces this structure?
Glutamine → Glutamate
Which reaction produces this structure?
Glycine →
What is shown in this process?
Degradation of a purine nucleotide: AMP
Compound A
- Name
- Structure
Adenosine monophosphate
(AMP)
Process 1
- Enzyme
- Reactions
- Nucleotidase
- → P
Compound B
- Name
- Structure
Adenosine
Process 2
- Enzyme
- Reactions
- Nucleoside phosphorylase
- P → Ribose-1-P
Compound C
- Name
- Structure
Adenine
Process 3
- Enzyme
- Reactions
- Adenine deaminase
- H2O →
- → NH3
Compound D
- Name
- Structure
Hypoxanthine
Process 4
- Enzyme
- Reactions
- Xanthine oxidase
- H2O →
- FAD → FADH2
Compound E
- Name
- Structure
Xanthine
Process 5
- Enzyme
- Reactions
- Xanthine oxidase
- H2O →
- FAD → FADH2
Compound F
- Name
- Structure
Uric Acid
Process 6
- Enzyme
- Reactions
- Uricase
- 2H2O + O2 → H2O2
- → CO2
Compound G
- Name
- Structure
Allantoine
What is shown in this process?
Degradation of a purine nucleotide: GMP
Compound A
- Name
- Structure
Guanosine monophosphate
(GMP)
Process 1
- Enzyme
- Reactions
- Nucleotidase
- → P
Compound B
- Name
- Structure
Guanosine
Process 2
- Enzyme
- Reactions
- Nucleoside phosphorylase
- P → Ribose-1-P
Compound C
- Name
- Structure
Guanine
Process 3
- Enzyme
- Reactions
- Guanine deaminase
- H2O →
- → NH3
Compound D
- Name
- Structure
Xanthine
Process 4
- Enzyme
- Reactions
- Xanthine oxidase
- H2O →
- FAD → FADH2
Compound E
- Name
- Structure
Uric Acid
Process 5
- Enzyme
- Reactions
- Uricase
- 2H2O + O2 → H2O2
- → CO2
Compound F
- Name
- Structure
Allantoine
De novo synthesis and nucleotide degradation occurs in the…
Cytosol
Uric acid → Allantoine reaction occurs in the…
Liver
Allantoin is excreted in the…
Urine
Which drug can be used to treat gout/uricosis?
How does it work?
Allopurinol
Competitive inhibition of Xanthine oxidase
Uric acid transport occurs by which 2 processes?
- Fast transport (80%)
- Slow transport (20%)
Cause of urate kidney stones in Dalmatians
- Fast transport gene of uric acid mutated
- Uricase active but no uric acid uptake
- Excretion: mostly uric acid, some allantoin
- Uric acid precipitated in the kidney
What is shown in this process?
Pyrimidine synthesis
Compound A
- Name
HCO3-
Process 1
- Enzyme
- Reactions
- Carbamoyl phosphate synthetase II
- Glutamine → Glutamate
- 2 ATP → 2 ADP
Compound B
- Name
- Structure
Carbamoyl-P
Process 2
- Enzyme
- Reactions
- Aspartate transcarbamoylase
- → P
Compound C
- Name
- Structure
Aspartate
Compound D
- Name
- Structure
N-carbamoyl aspartate
Process 3
- Enzyme
- Reactions
- Dihydroorotase
- → H2O
Compound E
- Name
- Structure
Dihydroorotate
Process 4
- Enzyme
- Reactions
- Dihydroorotate dehydrogenase
- NAD+ → NADH + H+ (Double bond formation)
- NADH + H+ → NADH (Double bond breakage)
Compound F
- Name
- Structure
Orotate
Process 5
- Enzyme
- Reactions
- Orotate phosphoribosyl transferase
- PRPP → P-P
Compound G
- Name
- Structure
Orotidylate
Process 6
- Enzyme
- Reactions
- Orotidylate decarboxylase
- → CO2
Compound H
- Name
- Structure
Uridine monophosphate
(UMP)
Process 7
- Enzyme
- Reactions
- UMP kinase
- ATP → ADP
Compound I
- Name
Uridine diphosphate
Process 8
- Enzyme
- Reactions
- Nucleoside diphosphate kinase
- ATP → ADP
Compound J
- Name
Uridine triphosphate
(UTP)
Process 9
- Enzyme
- Reactions
- CTP synthetase
- ATP → ADP
- Glutamine → Glutamate
Compound K
- Name
- Structure
Cytidine triphosphate
(CTP)
How many ATP are needed for pyrimidine synthesis?
7
What is shown in this process?
Degradation of pyrimidine nucleotides
Compound A
- Name
CMP
Process 1
- Enzyme
- Reactions
- CMP-deaminase
- H2O →
- → NH3
Compound B
- Name
UMP
Process 2
- Enzyme
- Reactions
- Nucleotidase
- → P
Compound C
- Name
Uridine
Process 3
- Enzyme
- Reactions
- Nucleoside phosphorylase
- P → ribose-1-P
Compound D
- Name
Uracil
Process 4
- Enzyme
- Reactions
- Pyrimidine dehydrogenase
- NADH + H+ → NAD+
- NAD+ → NADH + H+
Compound E
- Name
- Structure
Dihydro-uracil
Process 5
- Enzyme
- Reactions
- Dihydropyrimidinase
- H2O →
Compound F
- Name
- Structure
Ureido-propionate
Process 6
- Enzyme
- Reactions
- Ureidopropionase
- → CO2
- → NH3
Compound G
- Name
- Structure
β-alanine
Process 7
- Reactions
- → CO2
- → NH3
Compound H
- Name
Acetate
Compound I
- Name
HS-CoA
Resynthesis of nucleotides: For each nucleotide
Resynthesis of nucleotides: For purine nucleotides: Adenine
Resynthesis of nucleotides: For purine nucleotides in eukaryotes
Resynthesis of nucleotides: For purine nucleotides in prokaryotes
What is shown in this process?
Synthesis of deoxyribonucleotides
Compound A
- Name
- ADP
- GDP
- CDP
- UDP
Process 1
- Enzyme
- Ribonucleoside-diphosphate reductase
Process 1I
- Enzyme
Thioredoxin reductase
Compound A1
Compound A2
Compound A3
- Name
FAD
Compound A<span>4</span>
- Name
FADH2
Compound A5
- Name
NADPH + H+
Compound A<span>6</span>
- Name
NADP+
Compound A7
- Name
Dehydroascorbic acid
Compound A8
- Name
Ascorbic acid
Compound B
- Name
- dADP
- dGDP
- dCDP
- dUDP
Process 2
- Enzyme
- Reactions
- Nucleoside diphosphate kinase
- ATP → ADP
Compound C
- Name
dUTP
(also produced: dATP, dGTP, dCTP)
Process 3
- Enzyme
- Reactions
- dUTP-phosphatase
- → P-P
Compound D
- Name
dUMP
Process 4
- Enzyme
- Reactions
- Thymidylate synthase
- N5,N10 -methylene-FH4 → FH2
- Cobalamin →
Compound E
- Name
dTMP
Process 5
- Reactions
ATP → ADP
Compound F
- Name
dTDP
Process 6
- Reactions
ATP → ADP
Compound G
- Name
dTTP
Nucleoside phosphorylase hosts which process?
Deoxyribonucleoside releases Deoxyribose-1-P
During the degradation of deoxyribonucleotides, what is produced instead of β-alanine?
β-amino-isobutyrate
