• Catabolic and anabolic pathways
• Energy ﬂow in metabolism
• Overview of catabolism
• ATP + high energy compounds
• Locations and control of metabolism.
Metabolism: Highly integrated cell activity, involving hundreds of enzyme-catalyzed
reactions from which biomolecules are produced, maintained and destroyed, and by
which energy is obtained and used.
• Hundreds of integrated enzyme catalyzed rxns
• Maintains, produces and destroys biomolecules
• Energy is obtained or used
• Some reactions are common to all organisms. Variations in metabolic reactions are
mainly due to differences in free energy sources
Divided into two parts:
1. Catabolism: Sum of reactions of degradation in which nutrients and self
biomolecules are broken down to produce energy and monomers that are necessary
for the synthesis of biopolymers
2. Anabolism: Sum of reactions of biosynthesis in which biological molecules are
synthesized from smaller components.
Living Organisms are divided based on how they obtain free energy and carbon E Metabolism
1. Autotrophs: Use CO fro2 atmosphere as sole source of carbon.
Photoautotrophs (plants) obtain energy from sunlight. Chemolithotrophs Obtain
free energy through the oxidation of inorganic componunds.
2. Heterotrophs: Obtain carbon and energy from autotrophs.
Vitalism: Old doctrine, now rejected, that claims that living
organisms are fundamentally different from non-living entities
because they contain a non-physical component or are
governed by different principles than inanimate objects. Often
refers to a driving force, or vital energy that is equated to a
Antoine LaVoisier (1743-1794): Father of modern chemistry.
• Demonstrated nature of combustion
• Proposed the term oxygen.
• Developed new system of chemical nomenclature
• Wrote ﬁrst modern text for chemistry
• Responsible for agricultural reform, tax collection, and
gunpowder manufacture as a government ofﬁcial. Executed
during Reign of Terror.
Metabolic Pathways: Series of connected metabolic reactions that make a speciﬁc
1. Exergonic Reactions: Catabolic reactions
that break down metabolites to release free
2. Endergonic Reaction: Anabolic reactions
that synthesize simple metabolites to store
and invest free energy
Metabolites: Reactants, intermediates and
products of a metabolic pathway
Energy Flow in Metabolism
ADP, NAD , NADP , HPO