Chapter 6: Cellular respiration Flashcards
entropy
is a measure of the randomness of molecules in a system
when a physical system becomes more disordered, the entropy increases
enthalpy (H)
the total energy of a system
free energy (G)
the amount of energy that is available and can be used to promote change or do work
exergonic reaction
when a chemical reaction has a negative free-energy change
the products have less free energy than the reactants
ΔG<0
happen spontaneously
endergonic reaction
when a chemical reaction has a positive free-energy change
requires the addition of free energy
ΔG>0
catalyst
an agent that speeds up the rate of a reaction
enzymes
activation energy
inital input of energy used to overcome polar repulsion
EA allows molecules to be close enough for them to be re-arranged
enzymes lower EA to a point where a small amount of available heat can push the reactants to a transition state
lowering EA
straining reactatants:
positioning reactants close together
aerobic respiration (chemical formula)
6O2 + C6H12O6 = 6CO2 + 2H2O
glycolisis (chemical formula)
glucose (C6H12O6) + 2ADP 2- + Pi 2- + 2NAD+ = 2CH3(C=O)COO- + 2ATP 4- + 2NADH + 2H+ + 2H2O
phases of glycolisis
*cytosol
energy investment
cleavage phase
energy liberation
phosphofruktokinase
ATP: inhibitor
ADP: stimulator
breakdown of pyruvate
*mitochondrial matrix
enters through H+/pyruvate symporter
oxidation of pyruvate by pyruvate dehydrogenase
breakdown of pyruvate (chemical formula)
CH3(C=O)COO- + CoA–SH + NAD+ = Acetyl CoA + CO2 + NADH
*multiply by 2 if considering 2 pyruvates
citric cycle (chemical formula)
Acetyl CoA + 2H2O + 3NAD+ +FAD +GDP2- + Pi2- =
CoA–SH + 2CO2 + 3NADH + FADH2 + GTP4- + 3H+
