Why are fats the most energy rich macronutrients? Triglycerides have a much higher proportion of carbon-hydrogen bonds per gram molecular weight than carbohydrates. The overall processes of oxidative metabolism involves breaking the relatively weak carbon-hydrogen bonds and forming stronger carbon-oxygen and hydrogen-oxygen bonds. The principles of thermochemistry can help answer the question of why triglycerides possesses more food calories (9kcal/gram versus 4kcal/gram). In general, bonds with greater electronegativity difference tend to be stronger. Carbon hydrogen bonds are thermochemically weaker than carbon-oxygen bonds. They require less energy to break than the bonds being formed, which represents a net potential energy decrease. The principles of oxidation-reduction give a formal way to say the same thing. The weaker carbon-hydrogen bonds represent a reservoir of electrons which can ultimately participate in bonds with oxygen. While from a thermochemical perspective, we are breaking weak bonds and forming strong bonds. From an oxidation-reduction perspective, we say that oxygen is being reduced. The tendency of oxygen to form strong bonds is expressed in redox by its high reduction potential.












The WikiPremed MCAT Course is a comprehensive course in the undergraduate level general sciences. Undergraduate level physics, chemistry, organic chemistry and biology are presented by this course as a unified whole within a spiraling curriculum. Please read our policies on Privacy and Shipping & Returns.  Contact Us. MCAT is a registered trademark of the Association of American Medical Colleges, which does not endorse the WikiPremed Course. WikiPremed offers the customers of our publications or our teaching services no guarantees regarding eventual performance on the MCAT.


Creative Commons License
WikiPremed is a trademark of Wisebridge Learning Systems LLC. The work of WikiPremed is published under a Creative Commons Attribution NonCommercial ShareAlike License. There are elements of work here, such as a subset of the images in the archive from WikiPedia, that originated as GNU General Public License works, so take care to follow the unique stipulations of that license in printed reproductions.