3.1 Metabolism and Energy Flashcards
What is energy?
Energy is the capacity to perform work
Energy can be obtained by living organisms mostly in two ways:
Directly from the sun through photosynthesis or by eating energy-rich molecules
What are the two types of energy?
Potential energy, which is stored
Kinetic energy, which is motion
What is chemical energy?
Chemical energy is the potential energy of electrons, which depends on their position relative to positively charged atomic nuclei.
The farther the electrons are from the nucleus, the more potential energy they have.
What is bond energy
Bond energy is the amount of energy required to break or form a chemical bond. It is the same amount of energy needed to break as to form the bond.
What is activation energy (EA)?
Activation energy is the minimum amount of energy required to break bonds in the reactants and start a chemical reaction.
What is the transition state (Ts) in a chemical reaction?
The transition state is a temporary condition where bonds in the reactants are at their breaking point, and new bonds are ready to form in the products.
What is the first law of thermodynamics?
Energy cannot be created nor destroyed, only transferred or transformed from one object to another.
What is the difference between exothermic and endothermic reactions?
Exothermic reactions release energy (negative ΔH), while endothermic reactions absorb energy (positive ΔH).
What is entropy?
Entropy is a measure of disorder or randomness in a system. As disorder increases, so does entropy.
What is enthalpy (ΔH)?
Enthalpy is the total energy content of a system. A change in enthalpy is related to whether a reaction absorbs or releases energy.
What does the second law of thermodynamics (law of entropy) state?
The entropy of the universe always increases, meaning that systems naturally move towards more disorder unless energy is input to maintain order.
What is Gibbs free energy (G)?
Gibbs free energy is the energy available to do work in a system. It determines whether a reaction is spontaneous or not.
What is the formula for calculating the change in free energy (ΔG)?
ΔG = ΔH - TΔS, where ΔH is enthalpy change, T is temperature, and ΔS is entropy change.
If ΔG is negative, it is spontaneous
If ΔG is positive, it is non-spontaneous
What is an exergonic reaction?
An exergonic reaction releases free energy and has a negative ΔG, making it spontaneous.
