DP Biology (first assessment 2025)

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Question 22M.2.HL.TZ1.4b

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Date May 2022 Marks available [Maximum mark: 2] Reference code 22M.2.HL.TZ1.4b
Level HL Paper 2 Time zone TZ1
Command term Explain Question number b Adapted from N/A
b.
[Maximum mark: 2]
22M.2.HL.TZ1.4b
(b)

Explain the shape of the polypeptide chain at X.

[2]

Markscheme
  1. alpha helix / α helix
  2. type of secondary structure / second level of protein structure;
  3. maintained by hydrogen bonds;
  4. between C=O group and an N–H group;
Examiners report

This was one of the most successfully answered of questions, with better prepared candidates recognizing the alpha helix and explaining it in terms of hydrogen bonding.

Syllabus sections