DNA; Flashcards
What is DNA ?
= polymer
= made up of monomers, called nucleotides
=
What 3 components are nucleotides made from?
= phosphate head
= nitrogenous base
= pentose sugar- deoxyribose
with the bases which nitrogen forms the bond with the pentose deoxyribose sugar?
= NOT the 6 ringed structure, and an NH, not an NH2
What is DNA?
= a polynucleotide made from nucleotides condensendation reaction (producing water), together forming a phosphodiester bond, this forms a sugar phosphate backbone
=phosphate molecules is covalently bonded to the pentose sugar
How are phosphodiester bonds formed?
= condensation polymerisation
= the monomers are the nucleotides
= phosphodiester bond forms, and a water molecule is foemed from an OH and a hydrogen
What is the overall structure?
= 2 polynucleotide strands
= double helix
= polynucleotide strands are held together by hydrogen bonding
= base pairs: adenine + thymine
= guanine + cytosine
=
How do these base pairs of hydrogen bonding happen?
= adenine + thymine: 2 hydrogen bonding
= guanine + cytosine: 3 hydrogen bonding
= hydroge bonding is formed when a highly electrongeative element with lone pair of electrons is bonded with a hydrogen- the partial posiitbe hydrogen is attracted to the partial negative electronegative atom’s lone pairs
= needs to have a correct distance
THIS INVOLVES THE 6 NUMBER RING ONLY
= no other base pairings can happen as otherwise this is too close, the partially charged ions, and repel or not enough close
What is cis platin?
= anti cancer drug
= sqaure planar complex=
platnium metal ion
= 2 ammonia lingands
= 2 chloride io lingands
= always has 2 chloride ions next door to eachother
= binds to DNA in cancer cells
= prevents the cell from reproducing by cell diviosion and prevents repairing itself
=
What is a key idea about the chloride ions?
= complex are easy to displace
= can detach from the complex
= platnium can then bond to the nitrogen atoms on a guabine base within DNA
= another guanine can do the same with another cis platnin
=
