2.8.6

Large Biomolecules

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Large Biomolecules

In large biomolecules, such as polypeptides (proteins), multiple non-covalent interactions can occur between different parts of the same biomolecule to stabilize the structure.

Illustrative background for Amino acidsIllustrative background for Amino acids ?? "content

Amino acids

  • Proteins are made of amino acids.
  • Amino acids consits of a carboxylic acid croup, an amine group, and a variable R group.
  • Neighboring amino acids are joined via peptide bonds between the amine and carboxylic acid group.
  • Interactions between R groups creates the complex 3D tertiary structure of a protein.
  • The 3D structure is usually coiled or folded.
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Holding the 3D structure

  • There are many weak and strong interactions that determine the final 3D shape of the protein (e.g. ionic bonds and hydrogen bonds).
  • When the protein loses its 3D shape, it may no longer be functional.
    • This 3D structure is known as the tertiary structure of the protein.
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Ionic bonds

  • Charged amino acids have a positively or negatively charged ion in their side chain.
    • Charged amino acids can form relatively strong ionic bonds with other charged amino acids.
  • Ionic bonds between amino acids are quite rare.
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Hydrogen bonds

  • Hydrogen bonds also form between amino acids.
  • Hydrogen bonds are relatively weak but when there are many, the overall stability of the tertiary structure increases.
Illustrative background for Hydrophobic interactionsIllustrative background for Hydrophobic interactions ?? "content

Hydrophobic interactions

  • When protein folding takes place, the hydrophobic R groups of nonpolar amino acids lie in the interior of the protein, whereas the hydrophilic R groups lie on the outside.
    • These types of interactions are also known as hydrophobic interactions.

Jump to other topics

1Structure - Models of the Particulate of Matter

2Structure - Models of Bonding & Structure

3Structure - Classification of Matter

3.1The Periodic Table: Classification of Elements

3.2Periodic Trends

3.3Group 1 Alkali Metals

3.4Halogens

3.5Noble gases, group 18

3.6Functional Groups: Classification of Organic

3.7Functional Group Chemistry

3.8Alkanes

3.9Alcohols

3.10Halogenoalkanes

4Reactivity - What Drives Chemical Reaction?

5Reactivity - How Much, How Fast & How Far?

6Reactivity - The Mechanisms of Chemical Change

7Measurement, Data Processing & Analysis

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