Revision notes topic questions past papers

CIE AS Biology (9700) 2019-2021 Resources

REVISION NOTES 

 

  TOPIC QUESTIONS 

 

  PAST PAPERS

Page 50

The secondary structure of a protein with the α-helix and β-pleated sheet shapes

highlighted. The magnified regions illustrate how the hydrogen bonds form between the

peptide bonds

Tertiary

Further conformational change of the secondary structure leads to additional bonds forming

between the R groups (side chains)

The additional bonds are:

Hydrogen (these are between R groups)

Disulphide (only occurs between cysteine amino acids)

Ionic (occurs between charged R groups)

Weak hydrophobic interactions (between non-polar R groups)

This structure is common in globular proteins

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