Nucleic Acids Flashcards
(23 cards)
Uracil
2,4-dioxypyrimide
Thymine
2,4-dioxy-5-methylpyrimidine
Cytosine
2-oxy-4-aminopyrimide
Adenine
6-aminopurine
Guanine
2-amino-6-oxypurine
Reversible change of one one DNA base isomer to another
tautomeric shift (tautomerization)
2 forms of the molecules differing only in the location of a proton and a double bond
tautomers
Tautomer of Amino (NH2)
Imino (NH)
Tautomer of Keto (C=O)
enol (C-OH)
Major and minor grooves of DNA are essential for ___ of protein
binding
The only DNA with left helix rotation
Z DNA
Biologically dominant DNA
B DNA
Peculiar NA Sequences
Mirror repeat and inverted repeat
Symmetric sequence within each strand
Mirror repeat
Two copies of identical sequence in reverse orientation
Inverted repeat/ Palindrome
More secondary structures of DNA and RNA
- Internal loops
- Bulge loops
- Cruciform
- Hairpin
- Stem and Loop
- Cloverleaf (tRNA)
Where there are bases that cannon pair on both sides
internal loops
unpairs bases occur only on one side of the helix
bulge loops
DNA with a region of dyad symmetry
Cruciform
When it folds back on itself to form a double-helical segment in the region of the sequence
Hairpin
Similar with hairpin but the loops have many unpaired bases. It plays a role in attenuation
Stem and loop
Made up of three stem-loops
Cloverleaf structure
Significance of the other structures
- Stabilizing genome structure
- Recognition site for initiation of replication (ssDNA viruses)
- Serves as signal for initiation and termination of transcription
- Important in the function of NA (tRNA)
- Form the core of catalytic molecules (ribozymes) as binding sites
