Download - Vesicular transport
VESICULAR
TRANSPORT
INTRODUCTION
bubble-like membranous structure that stores and transports cellular products, and digests metabolic wastes within the cell;
an intracellular membranous sac that is separated from the cytosol by at least one lipid bilayer.
Secretory Vesicles
Transport Vesicles
Storage Vesicles
INTRODUCTION Transport across but not through the
membrane
Mode of transport of macromolecules
Requires metabolic energy but is independent of concentration gradient
CATEGORIES ENDOCYTOSIS
EXOCYTOSIS
TRANSCYTOSIS
ENDOCYTOSIS TYPES Phagocytosis- cell eating
Pinocytosis- cell drinking Receptor-mediated
ENDOCYTOSIS
Mechanisms : Constitutive Pathway
Clathrin-mediated Pathway internalization of many receptors
and the ligands bound to them—including, for example, nerve growth factor and low-density lipoproteins
Clathrin-mediated endocytosis
Clathrin coated vesicles – COP I & COP II
Clathrin
Adaptor Proteins
Dynamin Pinchase
Clathrin-mediated endocytosis
EXOCYTOSIS Non-Constitutive / Regulated
Pathway
Constitutive Pathway
Exocytosis-Endocytosis coupling maintains the surface area of the cell at its normal size.
INTRA CELLULAR VESICULAR TRAFFIC
Biosynthetic- Secretory pathway
Endocytotic pathway
Retrieval pathways
Vesicular traffic occurs in an orderly fashion
Selective & Specific
Rab proteins
SNARE proteins
Rab Proteins
SNARE Proteins – mediate vescile fusion
V-SNAREs – Docking proteins T-SNAREs – Latch proteins
APPLIED ASPECTSBotulism & Tetanus
AUTOPHAGY or AUTOPHAGOCYTOSIS
APPLIED ASPECTS
FAMILIAL HYPERCHOLESTEROLEMIA
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A colorized scanning electron microscope picture of a nerve ending that has been broken open to reveal the synaptic vesicles (orange and blue) beneath the cell membrane.