Bioenergetics Flashcards
Why do cells require energy?
Synthesis
Movement
Transport of ions against concentration gradient
Transport of ions against an electrochemical gradient
Generation of heat
What kind of reactions are essential for energy exchange in cells?
redox reactions
What is the energy currency of the cell?
Adenosine triphosphate
What are the bonds present in ATP?
2 phosphoanhydride bonds
1 phosphoester bond
How are the bonds in ATP broken?
Hydrolysis
What is hydrolysis?
Hydrolysis is a chemical reaction involving the breaking of a bond
in a molecule using water
Write an equation for the hydrolysis of ATP.
ATP+H2O -> ADP +Pi + energy
Name an endergonic and an exergonic reaction.
Endergonic - synthesis of protein
Exergonic - hydrolysis of ATP
What is the 1st law of thermodynamics?
Energy is conserved; it can neither be created nor destroyed
What is the 2nd law of thermodynamics?
In any closed system, the entropy (disorder) of the system will either remain constant or increase. “The universe will always tend towards increasing disorder”.
Define enthalpy.
H
The internal energy in a system
Define entropy.
The randomness or disorder in a system.
What is Gibb’s free energy?
G
The amount of energy capable of doing work during a reaction at constant temperature and pressure.
What is the change in free energy of a system determined by?
ΔG = ΔH – TΔS
What kind of reaction is present when ΔH > TΔS?
Endergonic
