Bioenergetics Flashcards
Endergonic vs exergonic
Endergonic takes place slowly
Exergonic takes place quickly
Positive delta G
Endergonic
Negative delta G
Exergonic
Rate of reaction is
Activation energy, NOT delta G
Delta G biochemical conditions
1 M reactants
1 M products
pH= 7.0
H2O = 55.5 M
298k
1 atm pressure
What is R
1.98 cal/mol
8.31 J/mol
1 mM equals
10^-3 M
Delta G for ATP to ADP
-7.3
How man negative charges in ATP
3.5
How many negative charges in ADP
2.5
Delta G ATP to AMP
-10.9
Which is more energetically favorable, ATP to ADP or ATP to AMP
ATP to AMP
When do we do ATP to AMP
Not often because it produces more energy than needed, 15.5
What happens when you couple an unfavorable reaction to ATP hydrolysis
ATP transfers phosphate to enzyme, leads to conformational change
Equilibrium equation
Delta G= -RTlnKeq
Near equilibrium equation
Delta =delta G + RTln [products]/[reactants]
Delta G + proceeds if
Products are very low or substrates are very high
How do you know what has a higher potential energy
More bonds=higher potential energy
In fed state (glycolysis), what increases
G6P
In fasted (gluneogenesis), what increases
G1P
What can be used isntead of ATP
nucleotriphosphates
Why don’t we used nucleotriphosphates instead of ATP
because it has an adenine and it looks different from guanine, cytosine
The enzymes don’t recognize it
High energy phosphate bonds
1,3 biphosphoglycerate
phosphoenolpyruvate
creatinine phosphate
acetyl coa
60% of energy from energy transfer is released in
heat
Shivering thermogenesis
asynchronous muscle contractions increase ATP consumptions
Brown fat non-shivering thermogenesis
Uncouple flow of protons across inner mitochondrial membrane
Thyroid hormone
Increases permeability of membrane for Na+, lose Na+ gradient
increases expression of Na+/K+ ATPase to regenerate gradient
Two types of consumption in mitochondria
Coupled to ATP synthase
uncoupled by protein leak
What happens in coupled to ATP synthase reaction
protein synthesis
Na+/K+ ATPase
Ca 2+ ATPase
Gluconeogenesis
Urea synthesis
Myosin ATPase
Organs that use the most energy per gram of tissue
Kidneys, heart, brain, liver
What happens if there’s an increase in Na+ and Ca2+ in cells
It causes cellular swelling because of no gradient, lower pH (more acidic)
Necrotic cell death
Structure of ATP
3 phosphates, one adenine connected to ribose
If keq=1
Delta G= 0
If keq>1
Delta G<0
If Keq<1
Delta G >0
Gibbs free energy
G=H - TS
What is H in gibbs free energy
Enthalpy, major contributor to G
Most of mitochondrial oxygen consumption is
Coupled to ATP synthesis
Small amount of mitochondrial oxygen consumption is
Uncoupled by proton leak
