1 A Uhcl Biochem Ii Exam3.1 - L5 Purine And Pyrimidine Metabolism

Front 1

--- Purine and Pyrimidine Bases ---
Purines have ### major forms.
Pyrimidines have ### major forms.

Back 1

2
3

Front 2

--- Purine Synthesis Pathway ---
1) Starting substrate is ***.
2) First real purine is ***. After this the
3) pathway splits into two branches yielding...

Back 2

1) ribose-5-phosphate
2) IMP(Inosine 5’-phosphate)
3) AMP and GMP

Front 3

--- Purine/Pyrimidine Synthesis/Salvage ---
LONG-FORM NAMES
1) Activated Ribose is AKA as...
2) Synthesized from starting material *** VIA
3) the enzymatic action of ***.

Back 3

1) PRPP (5-PhosphoRibosyl-α-PyroPhosphate)
2) α-D-ribose-5-phosphate
3) PRPP synthetase (PhosphoRibosyl PyroPhosphate synthetase)

Front 4

--- Nucleotide Biosynthesis ---
1) *** Synthesis Pathway is branched
2) *** Synthesis Pathway is not branched

Back 4

1) Purine
2) Pyrimidine

Front 5

--- Pyrimidine Biosynthesis ---
1) Starting substrate is *** which converted
2) into *** and *** in the cytosol of mammals
3) VIA the enzymatic action of ***.

Back 5

1) glutamINE
2) carbamoyl-phosphate and glutamATE
3) carbamoyl phosphate synthetase II

Front 6

--- Pyrimidine Biosynthesis ---
1st reaction resembles 1st step of urea cycle.
Except that *** replaces *** as the nitrogen donor.

Back 6

glutamINE replaces NH4+

[ammonium]

Front 7

--- Nucleotide Biosynthesis ---
One clear difference in the synthesis of...
pyrimidine nucleotides and purine nucleotides is that...
ribose-5-phosphate is linked after *** synthesis of the ***...
rather than during synthesis.

Back 7

ring
base

Front 8

--- Key Regulators of Pyrimidine Biosynthesis ---
1) ATCase is used by *** and CPS II is used by ***.
2) CPS II is inhibited by....
3) CPS II is activated by....

Back 8

1) Bacteria --- Mammals
2) UTP
3) ATP and PRPP

Front 9

ATCase(Bacteria) and CPS II(Mammals) are key regulators of *** biosynthesis

Back 9

Pyrimidine

Front 10

ATCase?

Back 10

(Aspartate TransCarbamoylASE)

Front 11

CPS II?

Back 11

CarbamoylPhosphate Synthase II

Front 12

PRPP?

Back 12

PhosphoRibosyl PyroPhosphate

Front 13

PRPP synthetase?

Back 13

PhosphoRibosyl PyroPhosphate synthetase

Front 14

IMP?

Back 14

inosine 5’-phosphate

Front 15

--- Regulation of Pyrimidine Biosynthesis ---
In animals, there is an additional point of regulation...
The enzyme *** is competitively inhibited by its product ***.

Back 15

OMP decarboxylase --- UMP

Front 16

--- Comparison of Carbamoylphosphate Synthases ---
CPS I --- CPS II
1) Pathway?
2) Nitrogen Source?
3) Located?
4) Activator?
5) Inhibitor?

Back 16

1) Urea Cycle --- Pyrimidine Biosynthesis
2) NH4+ --- Glutamine
3) Mitochondria --- Cytosol
4) N-Acetylglutamate --- PRPP
5) none --- UTP

Front 17

--- Formation of deoxyRNA---
1) Synthesized from ***.
2) Catalyzed by an enzyme called *** that uses
3) a free *** at an active ***(AA) in the R2 site.

Back 17

1) ribonucleotides
2) RR (Ribonucleotide Reductase)
3) radical --- tyrosine

Front 18

--- Synthesis of Deoxthymidylic Acid ---
dTMP is formed from dUMP thru the enzymatic action of ***

Back 18

thymidylate synthase

Front 19

Thymidine is also known as ***(based on uracil)

Back 19

5-methyluracil

Front 20

RR?

Back 20

Ribonucleotide Reductase

Front 21

--- Formation of deoxyRNA---
1) Synthesized from ***.
2) Catalyzed by an enzyme called *** that uses
3) a free *** at an active ***(AA) in the R2 site.

Back 21

1) ribonucleotides
2) RR (Ribonucleotide Reductase)
3) radical --- tyrosine

Front 22

--- Synthesis of Deoxthymidylic Acid ---
dTMP is formed from dUMP thru the enzymatic action of ***

Back 22

thymidylate synthase

Front 23

Thymidine is also known as ***(based on uracil)

Back 23

5-methyluracil

Front 24

RR?

Back 24

Ribonucleotide Reductase

Front 25

--- Degradation of Purines ---
End product in...
1) Primates, reptiles and birds
2) Other mammals, reptiles and mollusks
3) Aquatic invertebrates

Back 25

1) uric acid
2) allantoic acid or urea[CO(NH2)2]
3) ammonia [NH3]

Front 26

--- Degradation of Purines ---
1) End product *** is only sparingly soluble in water.
2) Overproduction results in deposits in *** and cartilaginous tissues.
3) Resulting in a disease called ***.

Back 26

1) Uric acid
2) kidneys
3) gout

Front 27

--- Degradation of Purines ---
1) Urease, used by *** Invertebrates,
2) catalyzes the hydrolysis of *** into...
3) *** and ***.

Back 27

1) Aquatic
2) urea [(NH2)2CO]
3) CO2 and ammonia[NH3]

Front 28

--- Degradation of Purines ---
1) Primates excrete ***. Other mammals undergo
2) an additional reaction involving the enzyme ***
3) which converts it into *** for excretion.

Back 28

1) uric acid
2) urate oxidase
3) allantoin

Front 29

--- Degradation of Purines ---
Final Metabolites from First to Last
1)
2)
3)
4)
5)

Back 29

1) Uric Acid
2) Allantoin
3) Allantoate
4) Urea
5) Ammonia

Front 30

--- Degradation of Pyrimidines ---
1) methylmalonic semialdehyde is an intermediate of....
2) this is diverted into...

Back 30

1) Thymine
2) TCA cycle

Front 31

--- Degradation of Pyrimidines ---
1) malonic semialdehyde is an intermediate of....
2) this is diverted into...

Back 31

1) Cytidine --- Uridine
2) fatty acid synthesis

Front 32

--- Degradation of Pyrimidines ---
Thymine
1) Intermediates?
2) Final product is...

Back 32

1) methylmalonic semialdehyde
methylmalonyl-CoA
succinyl-CoA
2) TCA cycle

Front 33

--- Degradation of Pyrimidines ---
Cytidine --- Uridine
1) Intermediates?
2) Final product is...

Back 33

1) malonic semialdehyde
malonyl-CoA
2) fatty acid synthesis

Front 34

--- Salvage Pathways for Purines ---
1) APRT catalyzes the conversion of....
2) into...

Back 34

1) PRPP and adenine
2) AMP

APRT (Adenine PhosphoRibosylTransferase)
PRPP (PhosphoRibosyl PyroPhosphate)

Front 35

--- Salvage Pathways for Purines ---
1) HGPRT catalyzes the conversion of....
2) into...

Back 35

1) PRPP and (hypoxanthine OR guanine)
2) IMP OR GMP

Hypoxanthine-Guanine PhosphoRibosylTransferase (HGPRT)

Front 36

Hypoxanthine is a purine/pyrimidine derivative whose nucleoside is called ***.

Back 36

purine --- inosine

Front 37

The purine base of Inosine is called...

Back 37

Hypoxanthine

Front 38

Name the forms of U in its Salvage Pathway...

Back 38

uracil [base]
uridine [base + ribose]
UMP [base + ribose + phosphate]

Front 39

Name the forms of T in its Salvage Pathway...

Back 39

thymine [base]
thymidine [base + deoxyribose]
dTMP [base + deoxyribose + phosphate]

Front 40

--- Salvage Pathways for Pyrimidines ---
base [E1] base+ribose [E2] base+ribose+P
1) E1 is called...
2) E2 is called....
3) What E releases P?

Back 40

1) [base] phosphorylase
2) [base] kinase
3) E1

Front 41

--- Thymine vs Uracil ---
T differs from U in that it....

Back 41

has an additional...
5' methyl group

Front 42

--- Thymine vs Uracil ---
U differs from T in that it....

Back 42

lacks a...
5' methyl group