FOM 3.2.2 Flashcards
Futile Cycle
when two metabolic pathways run simultaneously in opposite directions and have no overall effect other than to dissipate energy in the form of heat.
example: Glucose going back and forth from Glucose to G6P which helps with rapid response for up/downregulation
Near Equilibrium Reaction
- reaction goes back and forth
- example Creatine Kinase in muscles facilitate ATP being made by Phosphocreatine then being used by muscle (preworkout drink)
Essentially Irreversible
- products are so favored it’s essentially going one direction.
- In metabolism, equilibrium never reached so it basically won’t work backwards.
- Ex: azide modification of heme– the protein will likely be degraded before the azide dissociates
State Function
- delta G
- Independent of path
Equilibrium constant
Keq: magic ratio of products and reactant at equilibrium, the ratio the reaction is working towards
-Changing chemical nature of substrate or product will change this ratio
standard free energy
ΔG˚ = −RT ln K; this is derived at equilibrium when ΔG = 0 because potential energy is 0 at equilibrium. On the graph, it the vertical line that the reaction is working towards.
Oxidizing Agent:
-Drives reduction by accepting electrons (NAD+—> NADH)
Reducing Agent
-Reducing agent loses electrons via oxidation (Glyceraldehyde 3-P—–>1,3-Bisphosphoglycerate)
How does our body avoid equilibrium (death)?
-adding substrate (food) and removing product (CO2)
What enzyme can convert AMP + ATP to 2 molecules of ADP?
Adenylate Kinase
Free energy is independent of_enzyme or substrate____ and dependent on __enzyme or substrate_____
enzyme; substrate