Endomembrane System & Bulk Transport Process

Question 1

What does the endomembrane system include?

Answer 1

nuclear envelope, endoplasmic reticulum (rough and smooth), Golgi apparatus, vesicles, lysosomes, vacuoles, plasma membrane

Question 2

What is a endomembrane system

Answer 2

a membrane system interconnected by direct physical contact or transfer by vesicles

Question 3

What is the process for moving proteins out of the cell?

Answer 3

Synthesis, Tag and Package, Deliver

Question 4

What organelle is in charge of synthesising proteins?

Answer 4

Endoplasmic reticulum

Question 5

What organelle is in charge of tagging and packaging the synthesised proteins?

Answer 5

Golgi apparatus

Question 6

What organelle is in charge of delivering the synthesised proteins to where they need to go?

Answer 6

Vesicles. They can also fuse with membrane of organelles/the cell

Question 7

What two regions is endoplasmic reticulum composed of?

Answer 7

Smooth and rough

Question 8

What makes rough ER rough?

Answer 8

Ribosomes

Question 9

What are the functions of smooth ER?

Answer 9

Metabolism of carbohydrates, lipid synthesis for membranes, detoxification of drugs and poisons, storage of calcium ions (which are used as a signal in the cell)

Question 10

Can the amount of smooth ER be increased or decreased to meet demand?

Answer 10

Yes

Question 11

What are the functions of rough endoplasmic reticulum?

Answer 11

Involved in protein synthesis. Secreted and membrane-bound proteins enter the lumen (interior) of the rough ER and are processed by the rough ER and the rest of the endomembrane system for release of the cell or retention of the cell membrane

Question 12

Where does synthesis of cytoplasmic proteins occur on rough ER?

Answer 12

Free ribosomes

Question 13

What are the basic functions of the organelle Golgi complex?

Answer 13

Receives, modifies, sorts and ships proteins arriving from the rough ER

Question 14

What does the Golgi complex look like?

Answer 14

A series of membrane sacs and associated vesicles

Question 15

What role does each of the polar faces of Golgi complex do? (cis/trans?

Answer 15

Cis = vesicles from ER arrive and bind to the cis face.
Trans = Processed vesicles leave at the trans face

Question 16

List the names of the functions of the Golgi complex

Answer 16

Glycosylation, sorting proteins, directive vesicle trafficking

Question 17

What is glycosylation?

Answer 17

Addition (or modification) of carbohydrates to proteins. It is important for secreted or surface cell proteins.

Question 18

What are the names of the polysaccharides that Golgi may also secrete from the cell

Answer 18

Pectin and Hemicellulose

Question 19

What is the Golgi complex function called sorting proteins?

Answer 19

When the Golgi adds molecular markers to direct proteins to the correct vesicles before ‘budding’ from the trans face. This ensures it gets to the right location

Question 20

What is the Golgi complex function called directing vesicle trafficking?

Answer 20

When the Golgi adds molecular ‘tags’ to vesicles leaving the trans face to direct them to the correct targets. The tags are often short proteins exposed on the vesicle surface.

Question 21

Where do the tags direct vesicles once they leave the trans face?

Answer 21

lysosomes or secretory pathways or to plasma membrane to add membrane proteins. The tags act as docking sites once they reach these targets

Question 22

What are the names of the types of vesicles?

Answer 22

Transport vesicles, Secretory vesicles, vacuoles.

Question 23

What are vesicles?

Answer 23

membrane bound, cytoplasm/fluid filled organelles

Question 24

What is the name of the artificial vesicle that can be used for drug and vaccine delivery?

Answer 24

Liposomes

Question 25

What are the names for the ways bulk transport across the plasma membrane can be carried out?

Answer 25

Exocytosis, Endocytosis, Phagocytosis, Pinocytosis, Receptor-mediated endocytosis

Question 26

What is exocytosis?

Answer 26

Transports material out of the cell or delivers it to the cell surface

Question 27

What are the two types of exocytosis and what are they?

Answer 27

Constitutive exocytosis = releases ECM proteins (bone)
Regulated exocytosis = releases hormones and neurotransmitters

Question 28

What is endocytosis?

Answer 28

the cell takes in molecules and particulate matter at the plasma membrane

Question 29

What is phagocytosis?

Answer 29

cell ‘eating’ and the uptake of ‘food particles. it forms a phagocytic vacuole which is digested by lysosomes

Question 30

Where does phagocytosis occur in humans?

Answer 30

Macrophages

Question 31

What is pinocytosis?

Answer 31

cell ‘drinking’ and the uptake of extracellular fluid containing various solutes such at protein and sugars. an uptake vesicle is formed with the aid of a coat protein.

Question 32

What type of selection is pinocytosis?

Answer 32

Non-selective. It cannot choose what to bring into the cell

Question 33

What is receptor-mediated endocytosis?

Answer 33

a specialised form of pinocytosis where the cell can take up bulk quantities of specific substances. receptor proteins are used to selectively capture the required solute

Question 34

What are lysosomes?

Answer 34

membrane-bound organelles made by rER and Golgi body containing hydrolytic enzymes. They only work in acidic conditions which is why they are membrane bound.

Question 35

What do lysosomes do?

Answer 35

They degrade proteins, lipids, carbohydrates, nucleic acids and release breakdown products into the cell. They digest and release unwanted cellular materials.

Question 36

What is autophagy and why is it important?

Answer 36

The process of the lysosome digesting and releasing the unwanted cellular materials. It is important for cell health

Question 37

Why is lysosome function so important?

Answer 37

It keeps the cell healthy and is important for programmed cell death (where the cells intentionally die). It is crucial!!!!

Question 38

What are vacuoles?

Answer 38

Large vesicles derived from the rER and Golgi bodies. Food vacuoles are involved in phagocytosis

Question 39

Why are vacuoles important in plants?

Answer 39

The can perform lysosome like functions, large central vacuole absorbs water allowing plant cells to grow without large increase in cytoplasm, usually largest compartment in a plant cell.