Cells Alive 4: Vesicular transport

Question 1

What are the functions of the endoplasmic reticulum?

Answer 1

Protein biosynthesis
* Lipid biosynthesis
* Intracellular Ca2+ store

Question 2

What happens at the RER?

Answer 2

Folding of proteins

Question 3

What happens at the SER?

Answer 3

Synthesis of lipids

Question 4

What are some post-translational modifications in the ER?

Answer 4

Adding disulphide bonds to help stabilise the protein,

Question 5

What is Haemagglutinin an example of?

Answer 5

A chaperone protein

Question 6

Where does carbohydrate synthesis occur?

Answer 6

Golgi apparatus

Question 7

What is the fate of receptors?

Answer 7

can be recycled at the early endosome

Question 8

What is the fate of early endosomes?

Answer 8

Recycled into late endosomes

Question 9

What is the function of the lysosome?

Answer 9

To degrade products, and also to protect enzymes from being degraded

Question 10

What is the function of (COP I, COP II or clathrin)

Answer 10

Curved coat proteins, help form vesicles and tell the vesicle where to go

Question 11

What is cargo release mediated by?

Answer 11

Changes in pH

Question 12

What is the constitutive secretory pathway?

Answer 12

Proteins do not require a signal to be secreted through this pathway

Question 13

What is the regulated secretory pathway?

Answer 13

Requires specialised secretory cells and uses hormones, neurotransmitters etc.

Question 14

What is the structure of the endoplasmic reticulum?

Answer 14

It is made up of tubules and sacs surrounded by membranes

Question 15

Where are the ER tubules and sacs developed from?

Answer 15

the nuclear outer membrane, they are connected between each other and protrude into the cytoplasm

Question 16

What is the name of the space enclosed by the sacs?

Answer 16

lumen or ER cisternal space

Question 17

What does N-glycosylation do?

Answer 17

Attaches multiple branched sugars to the amide nitrogen of an Asn, this helps stabilise, protect from degradation and serves as a signal for interaction with other proteins

Question 18

Where are completed proteins sent after modifications?

Answer 18

Golgi apparatus

Question 19

What are some modifications that may occur at the golgi apparatus>

Answer 19

post-translational modification of proteins and lipids, O-linked glycosylation, sulphation

Question 20

how do snares work?

Answer 20

Each vesicle has a v-snare which is complimentary to a target t-snare, they wrap around eachother forming a trans-SNARE complex

Question 21

What is the trans-SNARE complex?

Answer 21

where membranes are locked together, this mediates membrane fusion