The Endomembrane System

nuclear envelope

double phospholipid membrane

nucleolus

area of the nucleus where ribosomes are made

heterochromatin

tightly packed chromatin

euchromatin

lightly packed chromatin

cytoplasmic fibrils

interact w/ the cytoskeleton and provides a docking site for cargo that needs to go in

the central pore control movement in and out of the nucleus is made up of…

4 rings of nucleoporin

nuclear basket

export of mRNA, transcription regulation, role in the cell cycle

rough ER

makes proteins that get exported from the cell OR that get used in another organelle OR integrated into a membrane

smooth ER

makes lipids

rough ER - making proteins in the cytoplasm : step 1

translation complex assembles

rough ER - making proteins in the cytoplasm : step 2

first 16-30 amino acids of the translated sequences are the signal peptide

rough ER - making proteins in the cytoplasm : step 3

signal recognition particle attaches to signal peptide → stops translation

rough ER - making proteins in the cytoplasm : step 4

translation complex moves to rough ER and attaches to SRP receptor

rough ER - making proteins in the rough ER : step 1

translation completes → complex disassembles

rough ER - making proteins in the rough ER : step 2

signal peptide is removed

rough ER - making proteins in the rough ER : step 3

polypeptide will fold w/ the help of chaperon proteins

rough ER - transport out of ER

• folded proteins find an exit receptor

• gets packaged into a vesicle

• vesicle has COPII (protein) on its surface

role of smooth ER in muscle cells

stores Ca²+ ions

function of golgi

process and package products from the ER

movement through golgi goes from…

cis → trans

cisterenal maturation

whole section moves down + new section gets made in place

vesicular transport

vesicle will move things through compartments

secretory vesicles

stuff getting exported or integrated into membrane

lysosome

vesicle that is responsible for degrading cell parts

transport from ER to Golgi is done by…

COPII

transport from golgi is done by…

VSNARE proteins integrated into vesicles from TSNARE at target location

clathin

protein that helps to build vesicles coming off the golgi