Biology 9700 · AS & A Level · Testing for biological molecules

Testing for biological molecules — practice question

Samples taken from a combination of biological molecules were tested. After iodine in potassium iodide solution was added to one sample, the mixture became black. A different sample was then tested using the biuret test, and the mixture turned purple. Which biological molecules were present in the mixture?

  • Aamylase and starch
  • Bcellulose and starch
  • Cphospholipid and cellulose
  • Dstarch and phospholipid

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