MBIO 2360 Lecture Notes - Lecture 19: Allotropy, Electron Donor, Electron Affinity
1 Dec 2016
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Document Summary
Living cells constantly perform work so they require energy: maintenance of highly organized structures, synthesis of cellular components, movement, many other processes. Cells carry out a remarkable variety of energy transduction i. e. conversion of one form of energy to another. Bioenergetics - is the study of energy relationships and energy conversion in biological systems. Biological energy transformations obey the laws of thermodynamics: 1st law - energy is neither created nor destroyed. Applies to biological systems etotal = 0: 2nd law - entropy of the universe is always increasing. The drive to randomize the gas makes process spontaneous and the randomization is capable of doing work. Living systems obviously create a problem for the second law because cells are highly ordered, non random entities - the entropy of the cellular materials decreases when a cell is formed. Proteins, nucleic acids, etc. represent large decreases in randomness. To compensate, energy must be supplied or larger increases in in entropy must occur elsewhere.
