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Metabolism
•
The sum of the
processes within
an organism
•
Living
organisms are in
a constant
struggle to
survive
•
All life
processes
require energy
•
Most commonly
used for of
energy is
Adenosine
Triphosphate
(ATP)
•
Most ATP in
made in the
mitochondria
All biochemical
pathways in your
body
Energy
• Energy is used anytime work is performed
• Climb a mountain
• Car travels down the road
• Link amino acids together
• Pump sucrose across a membrane
Many forms…
• Chemical
• Electrical
• Mechanical
• Light
• Thermal
Regardless of the form, energy exists in one of two states…
• Kinetic Energy
• Stored Energy
Kinetic Energy
• energy of motion
• Performs work by making
things move
Potential Energy
• stored energy
• chemical potential/gravitational energy
The First Law of Thermodynamics
The total amount of energy in any closed system is constant. Energy cannot be created
or destroyed; it can only be converted from one form to another. If a physical system
gains an amount of energy, another physical system must experience a loss of energy of
the same amount.
BOND ENERGY
• A measure of the strength or stability of the covalent bond
• Measured in KJ/mol (equal to amount of energy absorbed per mole
when the bond between atoms is broken
Important
• Energy is absorbed when product bonds break and energy is released when
product bonds form
Question • How will this affect the net amount of energy absorbed or released in the overall
reaction?
Energy Diagrams…
• the y-axis indicates the level of potential energy for the reactants before the
reaction and the products after the reaction has occurred
• If energy is released, the reaction is EXOTHERMIC
• If energy is absorbed, the reaction is ENDOTHERMIC
Bond energy and Potential energy have an inverse relationship
• The weaker the bond, the higher the potential energy
• The stronger the bond, the lower the potential energy
Enthalpy (∆ H)
This is calculated by using the following formula;
∆ H total = ∆ H final - ∆ H initial
Exothermic Reaction have a - ∆ H
Endothermic Reactions have a + ∆ H
Hey, PROVE IT!!!