Lecture 20 - Nucleotide Structure Flashcards
The “acid” portion of DNA or RNA arise from _____.
the phosphate/phosphoric acid
Nucleic acids are nucleotides attached to a _____.
sugar-phosphate backbone
Describe the sugar-phosphate backbone
the 5’ phosphate group of one nucleotide is attached to the 3’ -OH of another nucleotide
The sugar backbone is comprised of ______ bonds.
phosphodiester
Describe the hydrogen bonding in base pairing of nucleotides
A2T; G3C
The fully folded chromosome is found in what stage of mitosis?
the M-phase (chromosome segregation)
Uncoiled DNA is found in what phase of mitosis?
The I-phase (interphase)
Histone proteins + nuclear DNA is called _____.
chromatin
What differentiates ribose from deoxyribose sugars?
Ribose has a C2 and C3 -OH group; Deooxyribose has only a C3 -OH group
Bases + sugar = ______
nucleoside
base + sugar + phosphate = _________
nucleotides
Pyrimidines are the (large/small) ring stucture of nitrogenous bases.
small (Memory aid: big name, small ring)
Memory aid for purine and pyrimidine:
Pure As Gold: Purine - adenine, guanine
Reduces ribose sugars to deoxyribose sugars.
ribonucleotide reductase (removes C2 -OH group)
Why is production of nucleotides a highly energy favorable process?
Most nucleotides exist as a triphosphate. Cleavage of 2 Pi release energy and forms a nucleotide
Name and f(x)?
- Coenzyme-A
- synthesis and beta-oxidation of fatty acids - pyruvate oxidation
Name and F(x)?
- NAD
- acts as an electron carrier in redox reactions to form NADH
Name and F(x)?
- FAD
- Participates in redox reactions ot accept 2e to form FADH2
DNA/RNA is synthesized in the ______ direction.
5’-3’
Carbon 1 of sugar contains _____.
N-base
Carbon 2 of sugar contains ______.
either -H or -OH (deoxy vs ribose sugar)
Carbon 3 of sugar contains _____.
-OH group; forms phosphodiester bond with C5
Carbon 5 of sugar contains ______.
Phosphate group (binds with C3 -OH to form phosphodiester bond)
One turn of DNA is approximately ____ in length.
34 angstroms
How may base pairs per turn?
10 (~ every 3.4 angstroms)
What increased nucleotide ratio increases denaturation temperature? Why?
Increased G:C. Because G:C has 3 H-bonds, compared to the 2 H-bonds of A:T
Coded for by viral genome. Assists in virus replication by making DNA from RNA
reverse transcriptase
Enzyme that cleaves nucleic acid into oligomers (insert picture)
ribonuclease/deoxyribonuclease
Cleaves phosphdiester backbone (insert picture)
phosphdiesterase
Cleaves phosphate from nucleotide
nucleotidase (cleaves nucleotide to Pi and nucleoside
Cleaves base from nucleoside
Nucleosidase
Phosphodiesterase produces what oligomer?
nucleotide monophosphate (NMPs) or deoxynucleoside monophosphates (dNMPs)
Phosphoric acid, ribose sugar, and base is called a ______.
nucleotide
What same atom sources are shared between pyrimidines and purines?
Amino acids
How do pyrimidine and purine carbon sources differ?
Pyrimidine: HCO3
Purine: CO2
(Longer N-base = “longer” carbon source)
How do pyrimidine and purine THF sources differ?
Purine: formyl THF
Pyrimidine: methylene THF
Longer N-base = longer THF form
Sugars are attached to nitrogenous bases by what type of linkage?
a) alpha-glycosidic linkage
b) beta-glycosidic linkage
c) delta-glycosidic linkage
b) beta-glycosidic linkage
