12.158 | Fall 2011 | Undergraduate, Graduate

Molecular Biogeochemistry

Assignments

Students are required to critically evaluate the weekly topical article(s) and, taking it in turn, present a synopsis for about 10 minutes on some key of the papers.

Assignment 1

Topics for the 10-minute presentation about Mass Spectrometry.

  • Principles and advantages of Energy Filtering using the Electrostatic Analysers on a Sector Mass Spectrometer
  • Systematics of the mass spectra of aliphatic hydrocarbons; discuss ionization potentials, molecular ions, common and characteristic ion series
  • Systematics of the mass spectra of aliphatic fatty acid methyl esters; discuss ionization potentials, molecular ions, common and characteristic ion series
  • Systematics of the mass spectra of hopanoid hydrocarbons; discuss molecular ions, common and characteristic ion series
  • Systematics of the mass spectra of sterane hydrocarbons; discuss ionization potentials, molecular ions, common and characteristic ion series
  • Mass spectra of cyanobacterial hydrocarbons

Assignment 2

Topics for the 10-minute presentation about acyclic isoprenoids as biomarkers.

  • Biosynthesis of acetogenic lipids
  • Nomenclature of fatty acids (stereochemistry, unsaturations, etc.)
  • Acetogenic lipids in microbial mats (FAs and or/hydrocarbons; e.g., Jahnke et al., 2001)
  • Mass spectra of cyanobacterial hydrocarbons (Köster et al., 1999)
  • Acyclic isoprenoid biomarkers for anaerobic methane oxidation
  • Pentamethyl icosane – occurrence and isotopic composition

Assignment 3

Topics for the 10-minute presentation about bacterial hopanoids.

  • LC-MS analysis of functionalized hopanoids
  • Biomarkers for aerobic methanotrophy in deep sea mud volcano
  • Biochemical similarities and differences between SHC and OSC
  • Are 2-methylhopanoids good biomarkers for oxygenic photosynthesis?

Assignment 4

Topics for the 10-minute presentation about sterols.

  • Sterols as membrane components
  • Sterols as signalling molecules
  • Steroid biosynthesis as an oxygen sensor
  • Animal sterols
  • Sterol biosynthesis in invertebrates
  • Sterols of fungi
  • Steranes as proxies for paleoenvironment

Assignment 5

Topics for the 10-minute presentation about petroleum formation and occurrence.

  • Proxies for oxygen content in the past
  • δ13C of oils with different ages
  • Kerogen color index
  • Van Krevelen diagrams
  • Methods to improve oil recovery
  • Athabasca Pipeline Project
  • Abiogenic petroleum origin hypothesis. Drilling Project to reach the Moho

Assignment 6

Topics for the 10-minute presentation about oxygen deficiency in the past.

  • Definition of black shale
  • TEX86 index (e.g., Kim et al., 2010 GCA)
  • Ladderane lipids in sedimentary records (e.g., Jaeschke et al., 2009 Paleoceanography; 2009 GCA)
  • Nitrogen fixation & anoxia (e.g., Kuypers et al., 2004; Higgins et al., 2011 GCA)
  • Expansion of marine archaea during the Cretaceous (e.g., Kuypers et al., 2001 Science)
  • pCO2 reconstructions using d13C-biomarkers (e.g., Sinninghe Damste et al., 2010 Organice Geochemistry)
  • Isotopic ordering in lipids (e.g., Close et al., 2011 Geobiology)
Learning Resource Types
Lecture Notes
Presentation Assignments