Enzyme Mechanisms of Catalysis
Enzymes accelerate chemical reactions by lowering the activation energy through several catalytic strategies including acid-base, covalent, and metal-ion catalysis.
EnzymesEnzyme Regulation
Enzyme activity is regulated through multiple mechanisms including allosteric regulation, covalent modification, zymogen activation, and control of enzyme quantity.
EnzymesCholesterol Metabolism
Cholesterol is an essential sterol that modulates membrane fluidity and serves as a precursor for bile acids, steroid hormones, and vitamin D.
LipidsEicosanoids
Eicosanoids are signaling molecules derived from arachidonic acid that mediate inflammation, fever, pain, blood clotting, and smooth muscle contraction.
LipidsLipid Structure and Classification
Lipids are a diverse group of hydrophobic or amphipathic molecules that serve as energy stores, structural components of membranes, and signaling molecules.
LipidsLipoproteins and Lipid Transport
Lipoproteins are complexes of lipids and proteins that transport hydrophobic lipids through the aqueous environment of the bloodstream.
LipidsMembrane Lipids
Membrane lipids form the structural foundation of biological membranes, providing a selective barrier that defines cellular and organellar boundaries.
LipidsPhospholipid and Sphingolipid Metabolism
Phospholipids and sphingolipids are the major structural lipids of membranes, and their synthesis, degradation, and remodeling are tightly regulated.
LipidsDNA Replication
DNA replication is the process by which a cell duplicates its genome before cell division, ensuring each daughter cell receives an identical copy of the genetic material.
Nucleic acids