NA 2 Flashcards
Where is dietary NAs found
Food with cells (fruits, veggies, meats etc.
Does cooking eliminate NAs
No, it damages structure
Does saliva have NA- specific digestive enzymes
No
What does pepsin do in the stomach in NA digestion
cleaves nucleic acids into oligonucleotide fragments
What enzymes are in the small intestines
Ribonucleases and deoxyribonucleases
Are nitrogenous bases stored for later use?
No,they may be recycled
What happens to nitrogenous bases if they’re not needed for new NAs
They are metabolized
What is done with leftover phosphate
Used in synthesis of biomolecules or for skeletal mineralization
Where does nitrogenous base metabolism occur
Liver mitochondria
What does pyrimidine metabolism yield
β-alanine and β-aminoisobutyrate
What are the 4 steps of pyrimidine metabolism
-Deamination by a deaminase (cytosine only*)
-Dehydration by dihydropyrimidine dehydrogenases
-Hydrolytic ring opening by dihydropyrimidinases
-Hydrolysis by β-ureidopropionase
What happens with β-alanine
- can convert into malonyl coA (intermediate of FA synthesis) or excreted in urine
-also can convert into acetyl CoA and enter CAC cycle
What happens with β-aminoisobutyrate
Can convert into succinyl CoA (intermediate of CAC cycle) or excreted in urine
What are the 3 steps of purine metabolism
-Deamination by deaminases
-Hydrolysis to hypoxanthine (adenine-derived intermediate only)
-Oxidation by xanthine oxidase
What does purine metabolism yield
Uric acid
