Download 3.1 – Metabolism and Energy

3.1 – Metabolism and Energy
Read section 3.1 and explain the following terms into your notes.
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Metabolism
Metabolic pathways
Catabolism
Anabolism
Energy
Kinetic energy
Potential energy
Bond energy
Thermodynamics
First Law of Thermodynamics
Second Law of Thermodynamics
Entropy
Free Energy
Endergonic
Exergonic
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3.1 – Metabolism and Energy
Explain the following terms.
 Metabolism
Sum of all chemical (anabolic and catabolic) reactions in the cell. These
reactions provide life to the organism.
 Metabolic pathways
A specified sequence of reactions in the organism’s cells , catalyzed by
enzymes. (ie; cellular respiration).
 Catabolism
Breaking down larger molecules into smaller ones (individual subunits).
You finish with more molecules than you started with and in the process
release energy. (ie; cellular respiration)
 Anabolism
It is building larger molecules from smaller ones. You start with more
molecules than you finished with and in the process store energy.
(ie; photosynthesis)
 Energy
It is the capacity to do work. In living systems, it drives the metabolic
functions.
 Kinetic energy
This is the energy of motion. This is when the stored energy is being
used to drive the metabolic functions.
 Potential energy
This is stored energy. In living systems, this is the energy that is
available to the organism to carry out metabolism. It is commonly called
Chemical potential energy.
 Bond energy
This is the minimum energy required to form or break a chemical bond.
 Thermodynamics
This is the study of the changing energy forms.
 First Law of Thermodynamics
Energy cannot be created nor destroyed. It can only change forms. This
means that the total amount of kinetic and potential energy (or entropy
and free energy) in a system remains constant.
 Second Law of Thermodynamics
The tendency of any system is to move from order to disorder.
 Entropy
This is a measure of the randomness or disorder. When chemical
potential energy is converted, it is eventually lost from the system as
heat.
 Free Energy
This is the energy from a chemical reaction that is available to do work.
In living systems, this is the chemical potential energy.
 Endergonic
These are chemical reactions that require energy. In living systems, the
products contain more free energy than the reactants, thus creating
molecules that will provide energy to metabolism.
 Exergonic
These are chemical reactions that release energy. In living systems, the
products contain less free energy than the reactants, thus creating
molecules that will not provide energy to metabolism and will be
recycled.