Chemical Biology: Bioconjugation and Reporting on a Molecule in a Cell · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Tagging one protein inside a living cell

Science · Chemistry · ages 23-24
Name ______________________   Date ____________

  1. What is the price of labelling a native amine or thiol?

    • The reaction needs dry solvents
    • Native groups never react at all
    • The label lands on many proteins

  2. Why must cell labelling run near neutral pH?

    • The cell lives near neutral pH
    • Neutral pH makes dyes brighter
    • Acids always destroy reporters

  3. A position tag shows where the protein sits but not what it is doing.

    Circle one:   True   False

  4. Which control tests whether the signal is real?

    • Extra reporter with no wash step
    • A brighter microscope lamp
    • Cells missing the handle, labelled the same way

  5. Your target is scarce, so doses stay tiny. What must the reaction be?

    • Slow but gentle
    • Fast at low concentration
    • Hot and acidic

  6. You need the label on your protein alone. Which route do you take?

    • A native residue
    • An installed unnatural handle
    • A stronger dye dose

  7. Full labelling glows. The no-handle control glows faintly too. What do you conclude?

    • Part of the signal is background
    • All signal is your protein
    • The control was unnecessary

  8. Your question is about the protein's actions. Which reporter fits?

    • An activity reporter
    • A position marker
    • A brighter version of either
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Tagging one protein inside a living cell W1-mt_nsNwVhPRFN-s1

  1. The label lands on many proteins · Native groups sit everywhere. Easy reach means messy labelling.
  2. The cell lives near neutral pH · Match the cell or harm it. Chemistry must fit the living place.
  3. True · Each reporter has a reach and a limit. Position is this tag's reach.
  4. Cells missing the handle, labelled the same way · No handle means no true signal. Leftover glow is background.
  5. Fast at low concentration · Tiny doses need speed. A slow reaction would miss the target.
  6. An installed unnatural handle · Only your protein carries the handle. Clean address, clean label.
  7. Part of the signal is background · Faint glow without the handle is background. Subtract it before you claim.
  8. An activity reporter · Match the tool to the question. Actions need an activity reporter.
Worksheet · LightMySky