Enzyme inhibition can be either reversible or irreversible. Reversible inhibition is
characterized by rapid dissociation of the enzyme-inhibitor complex.
In competitive inhibition, the inhibitor resembles the substrate and binds active
site of the enzyme
Chapter 27: Fatty Acid Degradation
Fatty Acids Are Processed in Three Stages: Triacylglycerols can be mobilized by the
hydrolytic action of lipases that are under hormonal control. Glucagon and epinephrine
stimulate triacylglycerol breakdown by activatin
Chapter 24: Glycogen Degradation
Glycogen, a readily mobilized fuel store, is a branched polymer of glucose residues.
Most of the glucose units in glycogen are linked by -1,4-glycosidic bonds. At about
every tenth residue, a branch is created by an -1,6-g
Chapter 28: Fatty Acid Synthesis
Fatty Acid Synthesis Takes Place in Three Stages: Fatty acids are synthesized in the
cytoplasm by a different pathway from that of oxidation. A reaction cycle based on the
formation and cleavage of citrate carries acetyl
Chapter 31: Amino Acid Synthesis
An Overview of Nucleotide Biosynthesis and Nomenclature Nucleotides can be synthesized
entirely from small precursor molecules in a set of reactions called de novo pathways.
Alternatively, intact bases can be recycled and
Chapter 29: Lipid Synthesis (Cholesterol)
Lipoproteins Transport Cholesterol and TriacylglycerolsThroughout the OrganismCholesterol
and other lipids in excess of those needed by the liver are exported in the form of very
low density lipoprotein. After del
Chapter Eight: Mechanisms and Inhibitors of Enzymes
All enzymes operate by facilitating the formation of the transition state. Although
formation of the transition state varies from enzyme to enzyme, most enzymes
employ one or more of the following strate
An irreversible inhibitor dissociates very slowly from its target enzyme because it
has become tightly bound to the enzyme, either covalently or noncovalently.
Penicillin binds covalently, modifying enzyme transpeptidase (preventing
synthesis of bacteria
phenylalanine p-nitrophenyl ester. A product formed by chymotrypsins cleavage
of this is p-nitrophenolate (yellow color) measure absorbance of light.
Reaction showed an initial rapid burst of colored product, followed by its slower
formation as the react
The glycogen-mobilizing actions of protein kinase A are reversed by protein phosphatase
1, which is regulated by several hormones. Epinephrine inhibits this phosphatase by blocking its
attachment to glycogen molecules and by turning on an inhibitor. Insu