Energy and Metabolism Flashcards
(18 cards)
What is the first law of thermodynamics?
The total amount of energy in the universe is constant
What is bond energy
The measure of stability of a covalent bond. It is equal to the minimum energy required to break one mole of bonds between two atoms or the amount of energy released when a bond is formed
What is an exothermic reaction
A reaction that results in a net output of energy
What is an endothermic reaction
A reaction that results in a net absorption of energy
What is the second law of thermodynamics
In every energy transfer or conversion, some of the useful energy becomes unusable and increases entropy
What is entropy
Degree of disorder in thermodynamics
How is it possible for entropy to be decreased
Entropy must be increased somewhere else
What is spontaneous change
Spontaneous change is one that will continue once it’s own underway
What are some factors that determine if a reaction is spontaneous
Enthalpy
Entropy
Temprature
What is a non-spontaneous change
A reaction that cannot occur without a continual input of energy
What is free energy
Energy that can perform useful worn in the body
What is energy coupling
Spontaneous reactions release free energy which drive non-spontaneous reaction
What is an exergonic reaction
A spontaneous reaction that release free energy, occurs when change in free energy is negative
What is endergonic energy
Non-spontaneous reactions that require a constant supply of energy, occurs when change in free energy is positive
What is ATP’s purpose
ATP supplies free energy that can do useful work in the body
Describe the ATP/ADP cycle
ATP undergoes hydrolysis and loses an inorganic phosphate as well as free energy to form ADP, the free energy released drives reactions in other molecules. ADP under goes dehydration and an inorganic phosphate is added back with free energy from the breakdown of food to form ATP
Why can’t we use free energy from the breakdown pf food
The breakdown of food releases large amounts of energy which must be stored in small amounts in the ATP molecule
What is phosphorylation
Process of attaching a phosphate to an organic molecule which results in a gain of free energy in the molecule, this reduces stability and increases reactivity
