Cell Endomembrane System

Properties of Endomembrane System

Carries out a variety of tasks in the cell, including:protein synthesis and transport of proteins into membranes and other organelles;metabolism and movement of lipids; anddetoxification of poisonsmembranes of this system are related either through direct physical continuity or by the transfer of vesicles (sacs made of membrane)

Parts of the Endomembrane System

The Endomembrane System Includes:Plasma MembraneNuclear EnvelopeEndoplasmic ReticulumGolgi ApparatusLysosomeVacuoles

Parts of the Endomembrane System

Plasma Membrane

• separates cell from outside environment and regulates transport of molecules and signals into and out of the cell and communications with other cells

• Semi-permeable• Attachment point for the intracellular

cytoskeleton

Nuclear Envelope

• The nuclear envelope is a double membrane layer that surrounds the cell. It is dotted with thousands of nuclear pores which allows material to move into and out of thenucleus.

Endoplasmic Reticulum: Biosynthetic Factory

• an extensive network of membranous tubules and sacs (cisternae)

• the ER membrane separates the internal compartments of the ER (ER lumen)from the cytosol

• responsible for protein translation, folding and transportation of proteins

• Has 2 regions: Smooth ER and Rough ER

Endoplasmic Reticulum

Smooth Endoplasmic ReticulumWhat are the functions of smooth endoplasmic reticulum?– synthesis of lipids– carbohydrate metabolism– detoxification of drugs and poisons (especially in

liver cells)– stores Calcium ions

Rough Endoplasmic Reticulum

What are the functions of Rough ER?– attached ribosomes secrete proteins• Glycoproteins• secretory proteins depart from the ER by transport

vesicles which are formed in the transitional ER– creates membranes• grows by adding proteins and phospholipids to its

own membrane

Golgi Apparatus: Shipping and Receiving Center

A Golgi apparatus consists of flattened membranous sacs called cisternae.Functions:•Center of manufacturing, warehousing, sorting, and shipping•Has 2 sides: the cis face and trans face

Lysosome:Digestive Compartments

• Lysosome is a membranous sac of hydrolytic enzymes that an animal cell uses to digest macromolecules

Lysosomes: Digestive Compartments

Functions:–breaking down of macromolecules –digest worn out organelles, food particles

and viruses/bacteria

Vacuoles: Diverse Maintenance Compartments

• Are membrane bound vesicles whose functions vary in different kinds of cells– Food Vacuole–Contractile Vacuole–Central Vacuole