Bioenergetics Flashcards
What is the equation for delta G?
Why do we need this equation?
delta G = delta G standard + RT ln Q
- we need this to calculate delta G at non standard conditions
How does changing ratio of products to reactants influence Q and in turn delta G?
Increasing reactants/lowering products reduces Q and ln Q > making this value smaller and delta G more negative > closer to spont
Increasing products/lowering reactants does the opposite, more positive value increases delta G
What is the sum of energy in Endergonic reaction?
Products + reactants + activation energy of the exergonic reaction
What type of reaction generally requires more energy? Endergonic or Exergonic?
Endergonic - needs energy/heat to proceed
- requires activation energy of exergonic reaction
How do Endergonic reactions like G to G6P and F6P to F16BP become exergonic?
Coupled with ATP hydrolysis, net reaction is negative delta G. Think of as one simultaneous reaction
What is the delta G of ATP hydrolysis?
Around -30 kJ/mol
What is another alternative other than ATP hydrolysis that can make an Endergonic reaction more spont?
Direct product of this reaction into a favorable reaction? This reduces the amount of products and via le chatelier will push forward the formation of more products from the reactants available
What is the total activation energy of Endergonic reaction?
difference of Transition state energy - reactants + reactants energy
Two nucleotide triphosphates bond together and release a small molecule, in aq solution what is likely to happen?
Degrade into inorganic phosphate
- 2 high energy ATP bonding will release molecule of pyrophosphate
- likely will be hydrolysis into inorganic phosphate > Pi
Catabolism of fatty acids
- breaking down of fatty acids
- low NADH, high NAD+ > signals energy need
- more oxidized form > = energy need
- start B oxidation
Short chain fatty acids relating to energy
Can be beta oxidized to acetyl CoA > enter citric acid cycle
Microfilament vs Microtubule energy needs
Actin polymerization requires ATP hydrolysis and binding
Microtubule polymerization requires GTP
Both are polar: actin monomer asymmetric and microtubule is different subunit dimer
Hexokinase vs Glucokinase:
- location
- Km
- how each is inhibited
HK: all tissues, GK: liver
Km: HK is lower than GK, binding affinity for HK > GK
HK inhibited by elevated G6P; GK inhibited by hypoglycemia (correlated with BG level)
How does protein folding affect solution entropy?
Increases solution entropy, by reducing unfavorable cage of polar molecules around hydrophobic portions
How does protein folding affect protein entropy?
Reduces entropy by creating more ordered structure
- this loss in entropy is less than gain of entropy in solution, and other items
