Polymers + Amino acids + DNA Flashcards
1a State the meaning of the term transition metal complex
Central metal ion surrounded by ligands
1c Suggest why the oxidation state of chromium is zero in Cr(PF3)6
PF3 has no charge and so complex is also neutral
1e Name the type of bond between Na and H in ammonia
Covalent
1g Complete the equation to show the formation of one complex that contains chromium in its +3 oxidation state.
CrCl3 + 5H2O ->
[Cr(H2O)5Cl]Cl2
2ii When cisplatin is ingested an initial reaction involves one of the chloride ligands being replaced by water. Write an equation for this reaction
(NH3)2PtCl2 + H2O -> (NH3)2PtClH2O+ + Cl-
3c State and explain one risk associated with the use of cisplatin as an anticancer drug
Damages cells
Attach to DNA in normal cells
How can cis platin be used as an anti cancer drug
Inteferes with DNA replication
Explain why trans platin is an ineffective anti-cancer drug
Not stereospecific to DNA so cant bind
State a reagent and conditions needed for the hydrolysis in TLC
Conc HCL
Heat
Whats required in TLC at the top of beaker and why
Lid to prevent escape of vapour (could be toxic) so would need to do it in fume cupboard
Name a suitable developing agent in TLC and why its needed
Ninhydrin because amino acids are colourless
Explain strength of interaction between two cysteine R group differs from the strength of the interaction between a serine R group and an aspartic acid R group
2 cysteine groups would form a disulphide link
Serine and aspartic would form hydrogen bonds
Disulphide links are stronger than hydrogen bonds
Because disulphide bridges are covalent bonds
Suggest a suitable reagent for the hydrolysis of protein
Concentrated HCl
State the meaning of the term complementary when it is used to refer to DNA strands
A-T
C-G
Explain the orgin of the interaction represented by the dotted lines
O and N
Nitrogen and oxygen are very electronegative
Therefore C=O and N-H are polar bonds
Allows H-bond to form between O and H
Lone pair on O atom attracts Hdelta+
