BULK TRANSPORT Bulk Transport Used when a cell

BULK TRANSPORT

Bulk Transport • Used when a cell needs to transport large quantities of material into or out of the cell • Does not CROSS the cell membrane • Is a form of active transport as it requires ATP • There are two types of transport 1. Endocytosis 2. Exocytosis

Endocytosis • Bringing large amounts of material INTO the cell from the ECF • Two categories for endocytosis 1. 2. Phagocytosis Pinocytosis Phagocytosis (cell eating): is the bulk transport of solids into the cell Pinocytosis (cell drinking): is the bulk transport of liquids into the cell

Endocytosis: How Does it Work? • A solid contacts the cell membrane (receptor or distortion of shape) • The cell membrane sends out pseudopods • The pseudopods eventually surround and enclose the solid into a “sac” which is now located in the cytoplasm • The “sac” is called a phagocytotic vesicle • Lysosomes can attach to this vesicle, release enzymes into the vesicle and digest the solid further • Pinocytosis is similar except the liquids enter in a pinocytotic vesicle

Exocytosis: Transporting large amounts of material out of the cytoplasm and into the ECF • Works in a similar manner to endocytosis • The vesicles are produced to expel Hormones, proteins or waste material from the cell