Chapter 3.1 Flashcards
the transfer of electrons from one reaction to another in order to drive the second reaction
energy coupling
cells make _____ happen by supplying them with free energy released by _______
endergonic reactions; exergonic reactions
Living things constantly need free energy to grow, repair, move, and reproduce. How is this energy supplied?
ATP
energy cannot be destroyed or created in an isolated system but it can be converted from one form to another
The Law of Conservation of Energy (first law)
the energy that is available to do work
Gibbs free energy
a reaction will spontaneously occur if…?
GFE is less than 0 (exergonic) or if GFE is more than 0 (endergonic)
What are the different forms of energy?
chemical, electrical, mechanical. light, thermal
How do organisms obtain energy?
- through photosynthesis directly from the sun
2. consuming food (energy-rich molecules)
when energy changes from one form to another, no matter moves freely and entropy increases
2nd law
bond energy
the amount of energy needed to break a chemical bond
where is potential energy stored?
in chemical bonds
distance from the nucleus vs potential energy
the further the electron is away from the nucleus the more potential energy it has
kinetic energy
energy of motion
potential energy
stored in an object or molecule
metabolism
the sum of all chemical reactions in a cell or organism
activation energy
the minimum amount of energy that chemical reactants must absorb to start a reaction
transition state
a temporary condition during a chemical reaction where the bonds in the reactants are breaking and bonds in the products are forming
exothermic reaction
- a reaction in which energy is released, leaving the products with less chemical potential energy than the energy of the reactants
- the energy released as the bonds form is greater than the energy absorbed as they are broken
endothermic reaction
- a reaction in which energy is absorbed, giving the products more chemical potential energy than the reactants
- energy absorbed in breaking the bonds is greater than the energy released as new bonds form
entropy
the measure of disorder in a system
spontaneous change
a change that will once started, continue individually under ceratin conditions; does not require a constant supply of energy
a chemical reaction that releases free energy; the products have less free energy than the reactants
exergonic
a chemical reaction that absorbs free energy; products have more free energy than the reactants
endergonic
catabolic pathway
one in which energy is released and complex molecules are broken down into simple ones
a pathway in which energy is supplied to build complex molecules from simple ones
anabolic pathway
