Nucleic Acid Structure Flashcards
The type of RNA required to bring amino acids to site of protein synthesis? A. Micro rna B. mRNA C. rRNA D. tRNA
D
Nucleic acids are composed of ____ and _____________ backbone.
Bases and sugar phosphate backbone
DNA is _____ stranded and carries information in cell and ______ generations.
Double. Between generations.
DNA has a _________ helix structure.
Double
(-) phosphate backbone on outside.
Bases are stacked.
Denaturation of DNA disrupts _______ bonding, produces _______ strands.
Hydrogen. Single strands.
- DNA strands only separate. RNA only degraded.
- imp for hybridization, will still have template strand.
_______ and _________ conditions can denature DNA
Heat and highly basic conditions
________ are important to chromatin structure.
Histones
DNA in the nucleus is bound to ________
Histones
Adenine and thymine are joined by ______ double bond. Guanine and cytosine are joined by ____ double bonds
1, 2
GC more stable. More h bonding.
RNA replaces thymine with _____ and deoxyribose with ______
Uracil and ribose
Retroviruses can copy RNA to DNA with _____________. Which violates the central dogma.
Reverse transcriptase enzyme.
RNA -> DNA within host
_____ is important in the flow of information from DNA-> RNA -> protein.
tRNA
- has a cloverleaf shape.
- one loop has anticodon, complementary to Coding sequence for one amino acid in mRNA
_____ are site of protein synthesis.
Ribosomes
Not all of mRNA codes for ______. Only coding region is translated.
Protein
The _____ loops of RNA are important for enzymes to bind to. It can fold back on itself.
Irregular
RNA is generally ______ stranded.
Single
_______ rna is the structural and functional components of ribosomes. Majority of rna in most cells.
RRna
______ rna carries protein coding sequence. “What’s transcribed”
mRNA
_____ rna matches amino acid with codon. “Translation”.
tRNA
How RNA is different from DNA
- single stranded
- ribose sugar (instead of deoxyribose)
- U instead of T binds to A (difference is 1 methyl group)
5- fluorouracil only works in proliferating cells
A. True
B. False
A
s phase
5-fluorouracil stops ___________. Acts as a suicide inhibitor.
DNA synthesis.
A lot of drugs like to imitate the base______
Thymine
Nucleosomes are best described by which of the following?
A. Subunits of chromatin
B. DNA protein structures that contain histones in the core with DNA wrapped around the surface of the core.
C. Complexes of protein and the 45S rRNA precursors found in the nucleoli
D. Complexes of DNA and newly transcribed rna.
e. Single ribosomes attached to mRNA
B
_____ binds to DNA between nucleosomes
H1
* what makes it special. All but this one are found together in nucleosomes. “Beads” on the string
_____ is DNA + various proteins
Chromatin
“Beads on a string”
(-)
Supercoiled. DNA wrapped around
_____ are highly basic proteins with a high percentage of lysine and arginine. (+)
Interact with charge on _________ backbone.
Histones. Sugar phosphate.
________ DNA is the most common helix
B.
Right handed helix - turns clockwise.
By Watson and crick
Zidovudine is a _________ Analog reverse transcriptase inhibitor. (NRTI)
Nucleoside
Structurally identical to thymidine.
Once incorporated into DNA chain, halts DNA synthesis.
DNA synthesis requires a free ________ OH group?
3’
For DNA sequence 5’-ATCGATCGAT-3’, what is the sequence and polarity of the complementary strand?
3’-ATCGATCGAT-5’
______ pair denatures at lower temperature than G-C paid
A-T. Has less bonding so not as strong.
DNA strands are __________ and synthesized from a _______ to _____ direction.
Antiparallel.
5’ to 3’
The backbone of a DNA strand is composed of which of the following?
Phosphates and sugars
Deoxyribose is a derivative of ______ and lacks a _____ group on C2
Ribose. -OH
DNA nucleotides are composed of :
1.
2.
3.
Nitrogenous base, deoxyribose sugar, phosphate
PURe As Gold
Purines. A and G
2 rings
CUT the Pie
Pyrimidines. C, u, T
Nucleosides are ______ + _____
Base + sugar. N- glycosidic bond.
Nucleotides are _______ + _________
Nucleoside + phosphate.
