Endoplasmic Reticulum

Front 1

What is the role of Endoplasmic Reticulum in the production of proteins & lipids?

Back 1

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Front 2

What is the endoplasmic reticulum?

Back 2

- a network of enclosed tubules and membranous sheets that begin near the nucleus and extend across the cell.

- ER is continuous with the nuclear membrane.

Front 3

What are the functions of Endoplasmic reticulum?

Back 3

• Rough ER’s primary function is the synthesis and folding of new proteins

• Smooth ER’s primary function is the synthesis of new lipids

• The ER acts as a major calcium store, which is released upon certain cellular events (e.g. muscle contraction)

Front 4

How does ER contribute to the protein/lipid production?

Back 4

ER' membrane - the site of production of

*all the transmembrane proteins and lipids*

for most of the cell's organelles, including

# the ER itself,

# the Golgi apparatus,

# lysosomes,

# endosomes,

# secretory vesicles,

# the plasma membrane.

Front 5

Co-translational translocation

Back 5

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Front 6

Post-translational translocation

Back 6

operates in :

# Mitochondria,

# Chloroplasts,

# Peroxisomes,

# some Nuclear Proteins

Front 7

Insertion of single/multi-pass transmembrane proteins

Back 7

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Front 8

N-linked glycosylation

Back 8

Proteins are glycosylated on specific asparagine residues.

• Proteins are folded almost immediate as they enter the ER lumen – in conjunction with chaperone proteins.

• Key to this is the formation of di-sulphide bonds, which can occur in the oxidising environment of the ER.

Front 9

GPI-anchors

Back 9

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Front 10

Phospholipid synthesis & ordering

Back 10

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Front 11

What does the modification of proteins in ER include?

Back 11

- glycosylation;

- addition of GPI anchors

Front 12

asymmetry of lipids within membranes

Back 12

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