Using Compression Isotherms of Phospholipid Monolayers To Explore Critical Phenomena. A Biophysical Chemistry Experiment

Derek E. Gragson , Dan Beaman and Rhiannon Porter
Department of Chemistry and Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407
J. Chem. Educ., 2008, 85 (2), p 272
DOI: 10.1021/ed085p272
Publication Date (Web): February 1, 2008
History, Education, and Documentation

Abstract

Two experiments are described in which students explore phase transitions and critical phenomena by obtaining compression isotherms of phospholipid monolayers using a Langmuir trough. Through relatively simple analysis of their data students gain a better understanding of compression isotherms, the application of the Clapeyron equation, the balance between enthalpic and entropic contributions to the chemical potential, critical phenomena, and phase diagrams in general. Students use their data to determine the latent heat of transition, the entropy of transition, and the critical temperature for the liquid condensed to liquid expanded phase transition of a monolayer. Students also gain a general understanding of how molecular level changes in the structure of phospholipids, such as changes in chain length affect the structure and function of biological membranes.

Keywords (Audience):

Upper-Division Undergraduate

Keywords (Domain):

Biochemistry

Keywords (Pedagogy):

Hands-On Learning / Manipulatives

Keywords (Subject):

Biophysical Chemistry
View: Hi-Res PDF | PDF w/ Links

Tools

SciFinder Links

SciFinder subscribers: Click to sign in | Not a SciFinder subscriber? Learn more at www.cas.org

Explore by:

History

  • Received: August 03, 2009

Recommend & Share

  • Share on ACS NetworkACS Network
  • Add to FacebookFacebook
  • Tweet ThisTweet This
  • Add to CiteULikeCiteULike
  • Add to NewsvineNewsvine
  • Digg ThisDigg This
  • Add to DeliciousDelicious

Related Content