The Endoplasmic Reticulum and the Golgi Apparatus Flashcards
Describe in detail the structure/function of the endoplasmic reticulum and Golgi apparatus
The endoplasmic reticulum is part of which membrane system?
the endomembrane system
in the RER what is the name of the sac like structures held together by the cytoskeleton?
cisternae
what does the endoplasmic reticulum share its composition and structure with?
cell membrane/plasma membrane
what does the membrane of the endoplasmic reticulum do?
separates the cisternal space from the cytosol
What chemicals does the ER produce and store?
glycogen, steroids and other macromolecules
what does the ER sequester?
calcium
what does the ER do with proteins?
translation, folding and transport
where do the proteins created in the ER end up?
used in the cell membrane or exocytosed from the cell
what are the three varieties of ER?
rough endoplasmic reticulum
smooth endoplasmic reticulum
sarcoplasmic reticulum
why can the quantity of RER and SER change quickly?
differering metabolic needs
Which ER is studded with ribosomes
RER
When do ribosomes bind to the RER?
when the protein destined for sorting is synthesised
Which ER membrane is continuous with the outer layer of the nuclear envelope
RER
Where does the RER shuttle membrane bound vesicles to?
The Golgi apparatus
What ER membrane is key in producing lysosomal enzymes?
RER
What ER membrane is key in producing secreted proteins
RER
What ER membrane is key in producing integral membrane proteins
RER
What ER membrane is key in synthesising lipids and steroids?
SER
What ER membrane is key in metabolising carbohydrates
SER
What ER membrane is key in regulation of calcium concentration (particularly storage in muscle cells)
SER
What ER membrane is key in drug detoxification?
SER
What ER membrane is key in attachment of receptors on cell membrane proteins?
SER
What ER membrane is key steroid metabolism?
SER
What ER membrane is connected to the nuclear envelope?
SER
Why does the SER have increased surface area?
action or storage of key enzymes and the products of these enzymes
what is gluconeogenesis
a metabolic pathway that results in the generation of glucose from certain non carbohydrate substrates
Which enzyme in the liver converts glucose-6-phophate to glucose?
glucose-6-phosphatase (G6P)
What is the function of glucose-6-phosphatase (G6P)
Allows glucose to be formed from glycogen and released into the blood
Which tissue is glucose-6-phosphatase (G6P) absent in?
muscle tissue
What is the name of the type of SER found in smooth and striated muscle?
sarcoplasmic reticulum
what does the sarcoplasmic reticulum sequester and release once depolarised?
calcium (which triggers muscle contraction)
What is a microsome
small vesicles which reseal when ER is homegenised
