The Endomembrane System

Enzymes

________ present in the Golgi lumen modify the carbohydrate portion of glycoproteins by adding or subtracting individual sugar monomers.

Endoplasmic reticulum

________ (ER): a system of membranous channels and saccules.

Ribosome assembly

________ occurs in the nucleolus.

Chromosomes

________: composed of DNA and proteins= chromatin.

Perinuclear space

________: continuous with ER lumen.

endomembrane system

The ________ regulates protein traffic and performs metabolic functions in the cell.

Nuclear matrix

________: filamentous network; organizes chromosomes.

Smooth ER

________: synthesize lipids; metabolizes carbohydrates; detoxifies poison; stores calcium (Sarcoplasmic reticulum)

H2O + O2

Catalase then converts H2O2 into ________.

Golgi

The ________ modifies proteins and lipids that arrive from the endoplasmic reticulum.

Rough ER

________: studded with ribosomes and is the site of protein synthesis and processing.

Chromosomes

composed of DNA and proteins = chromatin

Nuclear matrix

filamentous network; organizes chromosomes

Inner nuclear membrane

specific proteins that act as binding sites for chromatin and for the nuclear lamina

Outer nuclear membrane

continuous with ER membrane; studded with ribosomes

Perinuclear space

continuous with ER lumen

Endoplasmic reticulum (ER)

a system of membranous channels and saccules

Rough ER

studded with ribosomes and is the site of protein synthesis and processing

Smooth ER

synthesize lipids; metabolizes carbohydrates; detoxifies poison; stores calcium (Sarcoplasmic reticulum)

Cis face

receiver (of vesicles)

Trans face

shipper (of vesicles)

Components of the endomembrane system

Nuclear envelope Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Plasma membrane

Lysosomes

Spherical organelles containing a single layer membrane Contain hydrolytic enzymes Involved in enzymatic breakdown of macromolecules and organelles

Peroxisomes contain

oxidative enzymes which remove hydrogens from specific substrates that in turn produces H2O2