by mariah ghant, saori ishizuka, and monica lin. the set of membranes found in eukaryotic cells...
TRANSCRIPT
The set of membranes found in eukaryotic
cells that carry out a variety of tasks in the cell
Tasks include: Synthesis of proteins Protein transport
into membranes and organelles out of the cell
Metabolism and movement of lipids Detoxification of poisons
Definition
Nuclear Envelope Endoplasmic
Reticulum (Smooth and Rough)
Golgi Apparatus Lysosomes Vacuoles Plasma Membrane
Major Parts of the Endomembrane
Nuclear Envelope
Structure Double Membrane Perforated by pore
structures Nuclear side is lined
with nuclear lamina Ribosomes on
cytoplasmic side
Function Encloses the nucleus Separates its
contents from the cytoplasm
Endoplasmic Reticulum Rough ER
Function Makes secretory
proteins (glycoproteins)
Keeps proteins seperated
Makes transport vesicles
“Membrane Factory” for the cells
Structure Many proteins and
phospholipids added to its own membrane
Has ribosomes continuous with
smooth ER
Endoplasmic Reticulum Smooth ER
Function Structure Synthesis of Lipids Metabolism of
Carbohydrates Detoxification of
Drugs and Poisons Stores calcium ions
Lacks ribosomes Membranes system
of interconnected tubules
Golgi ApparatusFunctions
Multiple interactions with the product of the ER (proteins): Modifies Stores Sends to multiple
destinations 2 poles of Golgi stack:
Cis face- receives vesicles containing ER products
trans face- dispatches vesicles
Structure
Consists of flattened membranous sacs (citernae)
LysosomesFunctions
Used in animal cells to digest macromolecules
Autophagy- process of recycling the cell’s own organic material
Phagocytosis- process of intracellular digestion in amoebas and small organisms
Structure
Membranous sac of hydrolytic enzymes
VacuolesFunctions
Their functions vary in different cells: Food Vacuoles- fuses with
the lysosome during the process of phagocytosis
Contractile Vacuoles- pump excess water out of the cell
Central Vacuole- located in mature plant cells; holds important organic compound reserves; main repository of inorganic ions
Major role in the growth of plants
Structure
Membrane-bounded vesicles
Container shape Contains pigments
that color cells
Plasma MembraneFunctions
Encloses the entire cell
Protein secretion occurs here after they’ve been carried by transport vesicles
Structure
Thin layer of cytosol between central vacuole and plasma membrane
The endomembrane interacts with the nucleus
via nuclear envelope The nuclear envelope is connected to the
rough ER, which encloses the nucleus
Interactions
1. Nuclear envelope is connected to rough ER2. Membranes and proteins produced by the ER flow in the
form of transport vesicles to the Golgi3. Golgi pinches off transport vesicles and other vesicles that
give rise to: lysosomes other types of specialized vesicles vacuoles
4. Lysosome is then available for fusion with another vesicle for digestion
5. Transport vesicle carries proteins to plasma membrane for secretion
6. Plasma membrane expands by fusion of vesicles; proteins are secreted from the cell
Review
Video
http://www.youtube.com/watch?v=PASnAaulK-Y