2. Introduction
2
• Metabolic processes – all chemical reactions that occur
in the body
There are two (2) types of metabolic reactions:
• Anabolism
• Larger molecules
are made from
smaller ones
• Requires energy
• Catabolism
• Larger molecules
are broken down into
smaller ones
• Releases energy
8. 8
Enzymes are globular proteins that promote chemical
reactions by lowering the activation energy required to
start the reaction and enhancing the reaction rate.
They are catalysts that do not get chemically changed in
the reaction themselves .
Since they are not consumed by the reaction, they are
needed only in very small quantities.
Enzymes are specific and act only on particular
substrates. There are enzymes that make bonds and
synthesize molecules and there are those enzymes that
break bonds and degrade molecules into smaller
molecules.
10. Cofactors and Coenzymes
10
• Cofactors
• Make some enzymes active
• Non-protein component
• Organic Ions or coenzymes such as zinc, copper,
calcium, or iron.
• Coenzymes
• Organic molecules that act as cofactors
• Small organic molecules that are often vitamins or
derived from vitamins.
Enzymes are often inactive until combining with cofactors
or coenzymes.
11. Factors That Alter Enzymes
11
• Factors that alter enzymes:
• Heat
• Radiation
• Electricity
• Chemicals
• Changes in pH
13. 13
Important Points in Chapter 4:
Outcomes to be Assessed
4.1: Introduction
Define metabolism.
Explain why protein synthesis is important.
4.2: Metabolic Processes
Compare and contrast anabolism and catabolism.
Define dehydration synthesis and hydrolysis.
4.3: Control of Metabolic Reactions
Describe how enzymes control metabolic reactions.
List the basic steps of an enzyme-catalyzed reaction.
Define active site.