Life Science 2 lecture 5

Life Science 2 lecture 5 - Quantity of energy doesn't...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Life Science 2 (lecture 5) I. Using receptors to move molecules into cells II. The energetics of cell reactions III. Enzymes speed reactions without being consumed -------------------------------------------------------------------- I. Using receptors to move molecules into cells See lecture 4 ------------------------------------ II. The energetics of cell reactions Potential Energy (Stored energy) Vs. Kinetic Energy (Energy in movement) First Law of thermodynamics: Within closed system, energy is neither created nor destroyed. Second Law of thermodynamics: Not all energy can be used. The usable portion is decreasing.
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Quantity of energy doesn't change. Quality does. H = G + TS where H = Total Energy, G = Free Energy (usable energy), T = Temperature, S = Entropy For a spontaneous process: G(final) - G (initial) = dG = negative (meaning spontaneous) Exergonic: release energy (eg. digest glucose) Endergonic: sucks up energy (eg. photosynthesis) TAKE HOME MESSAGE #2: Reactions run downhill; they will occur spontaneously if the end products have less free energy than the starting products. Q: How can a cell get endergonic reactions to occur? A: employ a temporary storage of energy...
View Full Document

This note was uploaded on 06/14/2008 for the course LS 2 taught by Professor Pires during the Spring '08 term at UCLA.

Ask a homework question - tutors are online