Purines and Pyrimidines Flashcards Preview

Molecules and Cells (Unit 1) > Purines and Pyrimidines > Flashcards

Flashcards in Purines and Pyrimidines Deck (12)
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1
Q

Nucleotides are formed from:

A

amino acids

ribose

formate

CO2

2
Q

Role of nucleotides

A
  1. Precursors to Nucleic Acids
  2. Energy Stores (metabolism)
  3. Enzymic effectors
  4. Group transfer reactions
  5. Physiological mediators (i.e. cAMP)
  6. Metabolite activation (UDP-glucose)
3
Q

Nitrogenous bases that exclusively secrete beta-alanine

A

Uracil and Cytosine

4
Q

Nitrogenous bases that exclusively secrete aminoisobutyrate

A

Thymine

5
Q

Nitrogenous bases that exclusively secrete uric acid

A

Adenine and guanine

6
Q

Deoxyribonucleotides Formation

NDPR (nucleoside diphosphate reductase or

ribonucleotide reductase reaction)

  1. Required for ______________synthesis
  2. Made from corresponding ribonucleotides via ______________ at # __________pos.
  3. Uses _________as reductant
A

DNA

reduction; 2

NADPH

7
Q

Purine synthesis may be considered to occur in three phases:

A
  1. Formation of IMP
  2. Conversion of IMP —–> GMP
  3. Conversion of IMP —–> AMP
8
Q

GOUT CONT’D

  1. Enzyme abnormalities
    a. ______________- deficiency
    b. _____________ deficiency
    c. _____________ variants
  2. Treatment
    a. alleviate ____________ episodes
    b. alleviate _______________
A

glucose 6-phosphatase

HGPRTase

PRPP synthetase

arthritic

hyperuricemia

9
Q

Synthesis of PRPP

PRPP used for::

_____________

____________

____________

____________

Inhibited by::

________________

______________

____________

Stimulated by _____

Ribose 5-Phos is from ___________

A

Syn of purines

Syn of pyrimidines

Syn of NAD

Salvage of nucleotide bases

dinucleotides

ADP

2,3-bisphosphoglycerate

Pi

HMS

10
Q

Nucleoside diphosphate reductase reaction

Reduction requires three proteins:

_____________

___________

_____________

Reduction of each

Substrate is regulated

By __________

A

a. NDPR
b. Thioredoxin red.
c. Thioredoxin

NTPs

11
Q

______________, exclusive product of thymine degradation, is important in monitoring effectiveness of cancer treatment

A

Beta-aminoisbutyrate

12
Q

SYNTHESIS OF THYMIDINE NUCLEOTIDES

  • MTX inhibits ________________________
    • ________________ Is a target in the treatment of cancer & Pneumocystis carinii pneumonia (PCP)
  • 5’-Flourouracil Inhibits __________
A

Dihydrofolate reductase

Dihydrofolate reductase

thymidylate synthase