ch. 8 Flashcards
Define Metabolism
the totality of an organism’s chemical reactions
What is a catabolic reaction?
releases energy by breaking down molecules.
What is an anabolic reaction?
absorbs energy by building molecules.
What is bioenergetics?
the study of how organisms manage their energy and resources.
What is thermodynamics?
the study of energy transformations.
What does the first law of thermodynamics state?
the energy of the universe is constant and is able to be transformed or transferred, but not created or destroyed.
What does the second law of thermodynamics state?
during every energy transfer, some energy is lost and increases the entropy of the universe.
What is entropy (∆S) and how does an increase in temp, enthalpy, and free energy affect it?
entropy is disorder. Increased temp causes increased entropy. Increased enthalpy causes decreased entropy. Increased free energy causes entropy to decrease.
What is enthalpy?
The amount of energy released or absorbed in a chemical reaction. So if ∆H is positive, it absorbs energy and if its negative it releases energy.
What is a spontaneous process?
Something that will happen given no external energy source (ex: ice melting)
How does ∆G affect spontaneity?
if ∆G is positive, it is nonspontaneous. If ∆G is negative, it is spontaneous.
What is free energy (∆G)?
the measure of a system’s instability and tendency to change to a more stable state.
What is an exergonic reaction?
releases free energy and is spontaneous.
What is an endergonic reaction?
absorbs free energy and is nonspontaneous
What is energy coupling?
the use of energy from an exergonic process to drive an endergonic one
