Chapter 8 Flashcards
Metabolism
the totality of an organism’s chemical reactions; transforms matter and energy
metabolic pathways
a series of chemical reactions occurring within a cell that are essential for its survival.
catabolic pathways
Break down complex molecules into simple building blocks and release energy.
anabolic pathways
Build up complex molecules from simple molecules and require energy.
what do catabolic pathways do with energy
release energy
what do anabolic pathways do with energy
consume energy
kinetic energy
energy doing work (generally energy in motion)
types of kinetic energy that are important to living organisms.
heat (thermal) and light (electromagnetic)
thermal (heat) energy
associated with random movement of atoms or molecules
electromagnetic (light) energy
movement of photons
potential energy
Stored energy that matter possesses because of its location or structure
how is energy stored
it can be stored as chemical energy
Why do organic molecules provide a rich source of energy?
Organic molecules have a lot of potential energy because they are easily broken.
Explain why ATP represents usable potential energy for a cell.
ATP is easily broken because the bonds of the ATP tail can be broken by hydrolysis.
What are the two laws of thermodynamics?
- states that the energy of the universe is constant. Energy can be transferred and transformed, but it cannot be created or destroyed. (law of conservation)
- states every energy transfer or transformation increases the entropy and heat of the universe.
Explain the concept of entropy. How does it relate to chemical reactions?
Entropy is the measure of molecular disorder or randomness. An increase in entropy favors the spontaneous chemical reaction; a decrease favors the nonspontaneous reaction.
What is enthalpy? How does it relate to change in free energy levels?
Enthalpy is a measure of energy in a thermodynamic system. Relates to free energy levels If a reaction is spontaneous. The change in enthalpy is the difference in bond energies between products and reactants.
Exergonic chemical reaction
energy is released (spontaneous)