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Topic 1: The Molecular Design of Life

Molecular design of life, major elements, and biomacromolecules.

Types of Macromolecules

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Which one of the following types of macromolecules correspond to the macromolecule 'adenosine triphosphate'.

 

Hydrophobic Compounds from Molecular Formulas

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Based on their molecular formula, which one of the following compounds is most likely hydrophobic?

 

Macromolecule Types Based on Chemical Structures

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Guide to Identifying the Chemical Structures of Macromolecules
Carbohydrates (monosaccharides)
  • Should have about the same number of oxygens as carbons.
  • Look for hydroxyl groups (–OH) attached to the carbon atoms.
  • Carbonyl groups (C=O) are often present as well.
  • Look for the base unit of CH2O.
  • Larger carbohydrates will form hexagon or pentagon ring-like structures.
Lipids (fatty acids)
  • Contain mostly carbon and hydrogen.
  • Very few oxygens and often no nitrogens.
  • Fats and oils will have carboxyl groups (–COOH) and ester bonds
  • Look for long chains or ring structures of only carbon and hydrogen.
  • Steroids have four interconnected carbon rings.
Proteins (amino acids and dipeptides)
  • Always have a nitrogen/amino group (–NH2 or –NH3+)
  • Always have a carboxyl group (–COOH or –COO-)
  • Identify the central Cα (alpha-carbon) attached to an amino group and a carboxyl group
  • Larger protein macromolecules will have a characteristic peptide bond (C–N)
  • Try to identify common side chains (R groups).
Nucleic acids (nucleobases)
  • Must have a nucleobase, rings containing carbon and nitrogen.
  • Larger nucleic acids will have a sugar backbone and phosphate groups.
Phosphate groups (–PO42-)
  • Found in all of the macromolecule types.
  • It is best to ignore them to not let them confuse you.
  • The breakdown of carbohydrates involves add phosphates.
  • Membrane lipids have phosphate head groups.
  • Many proteins are phosphorylated for regulatory purposes.
  • DNA has a phosphate backbone.
Molecule Information
Abbreviation ribulose
Full name D-ribulose
Molecular formula C5 H10 O5
Molecular weight 150.13 g/mol
Image link link to static image
Partition coefficient -2.6 logP
C/(O+N) ratio 1.0

Which one of the four main types of macromolecules is represented by the chemical structure of ribulose shown above?