DNA and anticancer drugsAQA A-Level Chemistry: Flashcards

What these 13 flashcards ask

What are the three parts of a DNA nucleotide?
Name the four bases in DNA.
How are nucleotides joined in one strand of DNA?
What is the DNA backbone?
What holds the two strands of the double helix together?
Which bases pair, and how many hydrogen bonds form?
What does complementary mean for DNA strands?
Why can the DNA strands separate without damaging the backbones?
What type of compound is cisplatin?
How does cisplatin bond to DNA?
Why does cisplatin prevent DNA replication?
Why does cisplatin have adverse effects?
What must society assess for a drug like cisplatin?

Exam questions on DNA and anticancer drugs

DNA is the molecule that carries genetic information in the nucleus of a cell. A single strand of DNA is a polymer, built up from repeating units called nucleotides.
Describe the structure of a single strand of DNA, including the position of the bases.2 marks
In cells, DNA exists as two strands wound together in a double helix. The two strands are complementary, and each strand can be used as a template when the DNA is copied.
Explain how hydrogen bonding between bases leads to the two strands of DNA being complementary.2 marks
Cisplatin, cis-Pt(NH₃)₂Cl₂, is a Pt(II) complex given by injection to treat some cancers. A dose is calculated from body surface area: 75 mg of cisplatin for every square metre. A patient has a surface area of 1.80 m². Relative atomic masses: Pt = 195.1, N = 14.0, H = 1.0, Cl = 35.5.
Cisplatin binds to DNA by a ligand replacement reaction. Explain what this means and how the bond between platinum and DNA forms.3 marks

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).