meaning it maintains membrane fluidity wide temperature range. 17. Catabolism involves
synthesizing large molecules and is endothermic. 18. Which of the following is a statement of
the First Law of Thermodynamics? fluidity over a. The entropy of the universe is decreasing b.
The entropy of the universe is constant c. Energy cannot be transferred or transformed d. Energy
cannot be created or destroyed. e. Energy is conserved by balancing its creation and destruction
For living organisms, which of the following is an important consequence of the First Law of
Thermodynamics? 19. a. The energy content of an organism is constant b. Entropy plays no role
in cellular equilibrium. c. The organism ultimately must obtain all of the necessary energy for
life from its environment The entropy of an organism decreases with time as the organism grows
in complexity d. e. Organisms grow by converting energy into organic matter 20. The
mathematical expression for the change in free energy of a system is AG -AH- TAS. Which of
the following is NOT correct? (a change) a· AS is the change in entropy, a measure of
randomness. b. is the change in enthalpy, a measure of potential energy. C. G and AS are
inversely related. d. An increase in AS indicates an increase in kinetic energy. e, G is the change
in free energy, and increases with increasing anabolic activity. 21. A chemical reaction that has a
positive G is best described as a. endergonic b. exergonic c. enthalpathic d. chemically
impossible e. catalyzed
Solution
21. A) Endergonic
Endergonic reactions are the ones in which there is absorption of energy , I.e. an energy input,
thus resulting in a positive value for delG. This value would be negative for the emergencies
reactions, where energy would be released.
20. B) DelH is the change in enthalpy, a measure of potential energy
This is incorrect because enthalphy measures the internal energy of the system, and thus
measures both potential energy and kinetic energy. Enthalpy = KE + PE.
19. C) The organism ultimately must obtain all of the necessary energy for life from its
environment.
This is because, there will not be formation of any new energy. This means, whatever energy is
at hand, people would have to use it, transform in one of the other manner and use it. Thus, all
required energy is present in the environment and has to be used from the environment.
18. D) energy cannot be created or destroyed
17. False
This is false because catabolism is the process in which there is the breaking of larger molecules