Post-translational Modification and Protein Turnover · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Edited after building

Science · Biochemistry & Molecular Biology · ages 18-19
Name ______________________   Date ____________

  1. What can a modification change about a protein?

    • Activity, location, partners or lifetime
    • Only its colour
    • Nothing at all

  2. Which is a post-translational modification?

    • Linking amino acids on the ribosome
    • Adding a phosphate group after building
    • Copying DNA into mRNA

  3. Tagging with ubiquitin sends a protein to the proteasome for shredding. True or false?

    Circle one:   True   False

  4. What drives the cell cycle from one phase to the next?

    • Waves of phosphorylation
    • New genes each phase
    • Chaperone bursts

  5. What does a short half-life say about a protein?

    • It is made from more mRNA
    • It is tagged for destruction faster
    • It is folded more tightly

  6. Synthesis holds steady but destruction speeds up. What happens to the protein level?

    • It rises
    • It stays the same
    • It falls

  7. Two proteins share a synthesis rate, but one has a shorter half-life. What follows?

    • It is translated faster
    • It never gets modified
    • It is tagged and recycled faster

  8. A cell reacts in seconds with no new mRNA made. How?

    • Ribosomes work a hundred times faster
    • Tags flip on-site proteins
    • Genes duplicate instantly
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Answer key

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

Edited after building W1-mt_93cxQwxxkh-s1

  1. Activity, location, partners or lifetime · One tag can flip activity, move the protein, or shorten its life.
  2. Adding a phosphate group after building · Modifications are chemical changes made after the chain is built.
  3. True · Ubiquitin marks old or damaged chains for recycling.
  4. Waves of phosphorylation · Phosphate waves flip regulators on schedule without new messages.
  5. It is tagged for destruction faster · Fast tagging means quick recycling, whatever synthesis does.
  6. It falls · The bathtub drains faster than the tap fills it.
  7. It is tagged and recycled faster · Equal taps with different drains mean different tagging rates.
  8. Tags flip on-site proteins · Proteins already on site get activated, moved, or destroyed.
Worksheet · LightMySky