Nucleotides Flashcards
purine
A and G
https://www.boundless.com/microbiology/textbooks/boundless-microbiology-textbook/microbial-metabolism-5/amino-acid-and-nucleotide-biosynthesis-54/purine-and-pyrimidine-synthesis-349-7356/
pyrimidine
C, T, and U
http://study.com/academy/lesson/pyrimidines-definition-examples-quiz.html
Keto-Enol Tautomerization
e- move around from where we draw the db on purines and pyrimidines
keto is common form
effects the H-bonding/base pairing
if happens during replication can cause mutation
why is deoxyribose the pentose sugar of choice for DNA
it is stable
ribose is unstable, 2 position -OH can break apart on its own
functions of nucleotides
1) precursor of nucleic acids
2) carriers of energy
3) carries of specific building blocks
4) regulatory signals
5) signal transduction cascades
6) methyl donor
7) coenzymes
Nucleotides as carriers of energy
the di- tri- bonds of attached phosphates have a lot of energy when broken
both have different amounts of energy (energy currency)
not unstable on their own
Ex: ATP provides energy for protein conformational changes
Nucleotides as carriers of specific building blocks
Ex: donates sugars in synthesis of glycogen and glycoproteins
Nucleotides as regulatory signals
Ex: acts as 2nd messenger mediating the response from certain hormones
cAMP very common
Nucleotides as signal transduction cascades
addition of PO4 to certain cellular proteins activates/deactivates them because of the large neg charge
PO4 comes from nucleotides
Nucleotides as methyl donors
they can add methyl groups to different proteins or DNA (epigenetics)
Ex: Adenosylmethionine (SAME) donates methyl groups in metabolic pathways
Nucleotides as coenzymes
participates in red-ox rxns, particularly sugar or FA catabolism where nucleotide carries an acyl group
Nucleotide Components
1) Nitrogenous Base -> purine or pyrimidine
2) 5-C sugar (pentose) -> ribose or 2-deoxyribose
3) phosphate (mono-, di-, or tri-)
