Thermodynamics, Energy, Enzymes, Redox Flashcards
Metabolism
sum of all anabolic and catabolic reactions in a cell connected in a network of reaction pathways
Anabolic reactions
-synthesize or “build” molecules
-higher free energy products
-store energy(endergonic)
-reduce entropy
-non-spontaneous
-positive delta G
Catabolic reactions
-degrade or “break” molecules
-lower free energy products
-release energy(exergonic)
-increase entropy
-spontaneous
-negative delta g
Free energy (G)
chemical energy available to do work, expressed as enthalpy(total energy) - entropy
Entropy
universal measure of spontaneity
Enzymes
proteins that reduce the activation energy of a reaction
Substrates
-interact with enzymes at the active site, forming an enzyme substrate complex with a close interaction that can change the shape of the enzyme
Induced fit
binding of a substrate to an enzyme causes it to change shape
allosteric effectors
molecules that bind somewhere other than the active site on enzyme and alter the shape to either inhibit or activate enzyme function
Negative feedback (aka Feedback inhibition) loops
use the product of a pathway to inhibit an enzyme at the beginning of the pathway
reaction coupling
combines a positive and negative delta g reaction in order to yield a new net negative delta g
hydrolysis of ATP (function & delta G #)
generate phosphorylate intermediate molecules of higher energy, -7.3 kcal/mole
ATP is regenerated from:
ADP+Pi
redox reactions
transfer electrons between molecules
Oxidation
loss of electrons by molecules
