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34 Cards in this Set
- Front
- Back
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the monomeric unit of DNA /RNA is made up of (three parts) |
a base (informational) a scaffold "Gerüst" (holds base) -> sugar a connector (links them together) -> Ph. |
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where does the a) base, b) phosphate bind |
a) #1 C b) #3+5 C |
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pyrimidine bases purin bases |
thymin, cytosin (1 ring) adenin, guanin (2 rings) |
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Uracil |
replaces thymin in RNA H instead of CH3 |
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bonds between hydrogen a) acceptors and b) donators c) how many? |
a) -N, =O b) -NH, -NH2 c) 2 AT, 3 GC |
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what causes acidity of nucleic acids? DNA. RNA |
phosphate groups are themselves acidic |
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role of nucleic acids (DNA; RNA) |
storage of genetic information (DNA) coding of proteins (RNA) energy carrier (monomers) |
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difference DNA, RNA |
OH group at #2 C missing in DNA thymine instead of uracil in DNA double stranded DNA |
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nucleoside? nucleotide? |
sugar + base sugar + base + phosphate |
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sugars of backbone in a) DNA b) RNA |
a) 2-deoxyribose b) ribose |
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direction of a) reading, b) synthesis + replication, c) binding |
a) 5' - 3' b) 5' - 3' c) antiparallel |
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3' end 5' end |
3' OH 5' phosphate |
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B-Form of DNA (6) |
"standard" structure 10.4-10.5 base pairs / turn 90° angle between axis and basepair minor groove + major groove huge difference DNA in major groove is easy accessible turns to right |
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A-Form of DNA (6) |
"rigid" form dehydration and high salt concentration 11 base pairs/ turn 71°-77° angle between axis and basepairs no huge difference between minor and major groove turns to right |
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z-Form of DNA (4) |
in some parts of chromosome for recognition + binding of regulator proteins 12 basepairs / turn turn to left! |
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supercoiling a) T b) L c) W |
a) twists (# of turns) b) linking number (# of links) #crossings/2 c) writhe (# of DNA crossing itself) |
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writhe: right to left left to right |
-1 +1 |
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Topoisomerases in general example |
detect unwound DNA fragments and repair this situation gyrase --> introduce negative supercoils |
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Topoisomerase I |
break one strand pass other strand trough gap reseal nick |
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Topoisomerase II |
break both strands pass another duplex region through gap reseal both nicks |
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Denaturation and melting of DNA |
separation of hydrogen bonds by: heating, base addition causes: change in UV absorption (260nm) called hyperchromicity |
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absorption of single stranded DNA.. |
..is 1.4 fold higher than in double stranded DNA |
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absorption of DNA is depending on.. |
.. the GC content |
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Tm is.. |
.. the melting temperature of DNA --> where 50% of DNA strand is separated |
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Renaturation + Reassociation |
2 step process: 1. nucleation (paired nucleotide sequences meet each other) 2. fast reestablishment of double strand at other locations |
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velocity of renaturation is depending on (4) |
-the concentration of cations (mask negative charge of phosphorus-group) -the temperature (optimal 25°C below Tm) -size and concentration of DNA -concentration of single strands |
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velocity of renaturation reaction equation |
C/C0 = 1/(1+k*C0t) |
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IUPAC Code R Y K M |
puRine = A or G pYrimidine = C or T Keto group = G or T amino group = A or C |
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IUPAC Code S W N also X |
Strong (3 hydrogen bonds) = G or C Weak (2 hydrogen bonds) = A or T aNy base |
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IUPAC Code B D H V - |
not A (before B in alphabet) = G, C or T not C (before D in alphabet) = A, G or T not G (before H in alphabet) = A, C or T bot T or U (before V in alphabet) = A, C or G gap |
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supercoiling eqaution white's formula |
L = T + W |
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Molecular Genetics in general |
studies structure and function of genes at molecular level employs the methods of genetics and molecular biology to elucidate function and interactions among genes |
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keto group |
R2C = O |
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amino group |
R-NH2 |
