Exam 3 Biochem-Lecture 35 – Flashcards
Unlock all answers in this set
Unlock answersquestion
| Deoxyribonucleotides are formed by |
answer
| the reduction of ribonucleoside diphosphates. |
question
All deoxyribonucleotides are synthesized from ........... by the enzyme ribonucleotide reductase. |
answer
| ribonucleotides |
question
nAll deoxyribonucleotides are synthesized from ribonucleotides by the enzyme ....... |
answer
ribonucleotide reductase. (highly regulated) |
question
Deoxthymidylate (dTMP) is formed by |
answer
methylation of deoxyuridine 5’-mono Phosphate (dUMP) |
question
| what is the precursor for all the pyrimidine nucleotides???? |
answer
| UMP |
question
nPyrimidine nucleotides are degraded to ....? |
answer
| b-amino acids |
question
Nucleotide mono-, di-, and triphosphates are ....... |
answer
interconvertible For example - UMP → UDP → UTP |
question
Specific nucleoside (X) monophosphate kinases make |
answer
nucleoside diphosphates
XMP + ATP -->XDP + ADP |
question
• A nucleoside diphosphate kinase, with broad substrate specificity,interconverts............ (this enzyme uses both ribo- and deoxynucleosides as substrates) |
answer
| dinucleosides and trinucleosides |
question
| Nucleotide coenzymes are |
answer
nNAD nFAD nCoenzyme A (CoA) |
question
NAD means |
answer
| nicotinamide adenine dinucleotide |
question
FAD means |
answer
| Flavin Adenine Dinucleotide |
question
nPRPP is the KEY molecule in |
answer
¨ de novo synthesis of purine and pyrimidine nucleotides ¨salvage of purine and pyrimidine bases ¨ and synthesis of NAD+. |
question
| PRPP means |
answer
| 5-phosphoribosyl-1-pyrophosphate |
question
| dUMP can be converted to dTMP using this enzyme: |
answer
thymidylate synthase |
question
| thymidylate synthase |
answer
| an enzyme targeted by anticancer drugs such as 5-flurouracil |
question
nThe regeneration of THF from DHF produced in the thymidylate synthase reaction requires |
answer
| dihydrofolate reductase |
question
| dihydrofolate reductase |
answer
| an enzyme targeted by the drug, methotrexate. |
question
| Methotrexate is |
answer
| Folic acid antagonist |
question
| Acyclovir is analog |
answer
| purine |
question
| AZT is a ...... analog |
answer
| pyrimidine |
question
nAcyclovir a purine analog, and AZT a pyrimidine analog are used in the treatment of |
answer
| HSV and HIV infections. |
question
| Acyclovir, a purine analog, and AZT a pyrimidine analog are |
answer
| antiviral agents |
question
| 6-Mercaptopurine is |
answer
| purine analog |
question
| 5-Fluorouracil is |
answer
| pyrimidine analog |
question
| Cystonesine arbinoside is |
answer
| pyrimidine analog |
