3.4: Cellular Energy Flashcards
What is the 1st law of thermodynamics?
Energy can neither be created nor destroyed, it can only be transferred.
What is the second law of thermodynamics?
Every energy transfer increases the entropy (disorder) of the universe
How is order (entropy) maintained in a system?
Through energy coupling. For each exergonic reaction, there is an endergonic one.
How are cellular processes powered?
Sunlight is captured and transformed into chemical energy. Each process transforms the chemical energy into different kinds to make it more useful.
What is an endergonic reaction?
An endergonic reaction needs to absorb energy (from a lower free energy to a higher free energy.).
What is an exergonic reaction?
An exergonic reaction releases free energy (from a higher free energy to a lower one).
What is energy coupling?
An exergonic reaction (releases energy) drives the endergonic reaction (takes in energy)
What happens if an organism has a loss of energy or energy flow?
It would no longer live as it needs reactions to occur for daily survival.
Why does the cell undergo the step-wise function to control energy release through cellular respiration?
It allows for a more controlled and efficient energy transfer, so as not to increase the entropy of the system.
In a metabolic pathway, how does the product of one reaction relate to the reactants of the subsequent reaction?
The product of the first reaction becomes the reactant for the second reaction in energy coupling.
