Distinguish between catabolic and anabolic pathways Correct Answer-
Catabolic pathways involve the breaking down of macromolecules into
smaller molecules, Anabolic pathways involve the combining the small
molecules into large macromolecules
Name and define each of the terms in the above equation (dG = dH-TdS)
Correct Answer-dG is the overall change in free energy, dH is the
overall change in enthalpy, T is the temperature, dS is the overall change
in entropy
Distinguish between DG, DG°, and DG'° Correct Answer-DG is the
regular change in free energy for a reaction, the DGo is DG at 298K,
1atm, and 1M of products. TheDGio is DGo except at a pH of 7 and
without the 1M designation
What is the sign of DG'° when the reaction proceeds in the written
direction? Correct Answer-negative
Compare the free energy content of acid
anhydride and ester bonds. Correct Answer-Acid anhydrides have a
much higher DGio
Which term in the Gibbs equation can be used to predict whether a
reaction will proceed? Correct Answer-DG is the term as its sign will
tell you in which direction the reaction will proceed
, What does DG tell you about the rate of the reaction? Correct Answer-
nothing
What affect do enzymes have on DG? Correct Answer-none
Give at least two reasons why DG'° is such a large negative number
(ca. -30.5 kJ/mol) for the reaction (Fig. 13-11, p. 508):
ATP + H20 ® ADP + Pi Correct Answer-Charge separation that results
from hydrolysis relieves electrostatic repulsion among the four negative
charges on the ATP, the product of the
Although the free-energy change for ATP hydrolysis is -30.5 kJ/mol,
ATP is kinetically stable in water in the absence of enzymes. Suggest
why Correct Answer-Because the activation energy of ATP hydrolyzing
on its own is very high
explain why thioester, but not
oxygen ester, bonds are high energy. Correct Answer-thioester has a
higher energy than oxygen esters because they have less resonance
stabilizaiton than oxygen esters
It is possible for a reaction with a positive DG'° to be driven by a
coupled