Cell Compartmentalisation,

Question 0

Mitochrondria and pm

Answer 0

Involved in inclusion of pm

Question 1

Pinching of specialised pm

Answer 1

Cause formation of organelles interior - similar to exterior of cell

Question 2

Organelles involved in cycles of membrane budding and fusion

Answer 2

Golgi, rer, vesicles, ser, peroxisomes, lysosomes, endosomes,

Question 3

4 distinct families of intracellular compartments?

Answer 3

Nucleas
Organelles Involed in secretory/endosomes pathway
Mitochrondria - fusion and fission replication - maternal dna - circular
Plastids (plants)

Question 4

Nuclear por proteins modified with ?

Answer 4

O-N-acetyl glucosamine - post translational modification - RER

Question 5

Why is GlcNAc important?

Answer 5

Modification of protein integrates metabolic information

Amount dependant on Biosynthetic pathway

Question 6

Hexamine biosynthetic pathway?

Answer 6

Glucose, glucose 6 p, fructose 6 p, (aa met) glucosamine 6 p, n acetylglusosamine 6 p, n acetyl glucosamine 1 p, (nucleotide met) UDP-N acetyl glucosamine

Question 7

Stressfull stimuli lead to increase of the ….

Answer 7

O N acetyl glucosamylation of Nuclear pore proteins (NUP)

Question 8

Examples of stressfull stimuli O-GlyNAc ylation of NUPs

Answer 8

Heat shock, uv radiation, hypoxia, oxidative/reductive stress, ethanolic stress, trauma haemorrhage, cell cycle arrest, osmotic stress

Question 9

NUP stim. What? (2)

Answer 9

Gene expression and cell cycle genes

Question 10

Example of NUP

Answer 10

Mtor and MP153 - located at npc - associated w/ active transcription - filaments - translocated mrna into cytosol

Question 11

Tumour? And genes

Answer 11

Mutation of protooncogene - oncogene - uncontrolled cell division

Question 12

NUP98 is example of?

Answer 12

Gene fusions (bind to other genes) + hematopoietic malignancies

Question 13

Hematopoeitic malignancy!

Answer 13

Change in myeloid linage - impaired t,b cell differentiation

Question 14

Different cells have different amount of organelles

Answer 14

Therefore different genes switched on/off.

Eg pancreas - hormones - RER - 60% pf total plasma membrane

Question 15

Ribosomes with mrna that codes for secretory proteins?

Answer 15

Binds to rer via ribophorins

Question 16

Nuclear and peroximal proteins?

Other example of proteins folded?

Answer 16

Folded specifically - cytoplasm

To peroxisomes and npc ( receptor mediated)

Chloroblast - specific folding of proteins

Question 17

ER signal?

Answer 17

Specific sequence KDEL n terminus (20-24 aa, hydrophobic)
Bind to srp - er membrane
Ribosome bind to er membrane
Signal peptidase cleaves specific sequence

Question 18

Biogenesis pathway of mito proteins?

Answer 18

Nascent protein - precursor protein - TOM - intermembrane space

Question 19

PROTEASOMES?

Answer 19

20-24 protein subunits
Cylindrical
Hydrolyse incorrectly folded proteins
Links to incorrect protein via ubiquinated protein

Question 20

Ubiquinated protein

Answer 20

9000aa,
Cytosol
Link proteasome enzyme to incorrectly folded protein

Question 21

RER incorrectly folded proteins

Answer 21

Unfolded protein response (degradation pathway) -> to cytoplasm
Ubiquinated protein
Proteasome (degradation)

Question 22

Molecular chaperones?

Answer 22

Assist protein folding in ER - golgi complex - ecm
Calnexin (membrane bound protein-hydrophobic) and
calreticulin cycle (luminal protein - soluble in cytosol of rer)

Make more reliable and efficient

Question 23

Cycle of glycosylation and deglycosylation ->

Answer 23

Detect folding of protien

Question 24

Protein point mutation?

Answer 24

Change : base sequence, primary, secondary, tertiary structure.

protein incorrectly folded. Irreversible.

Question 25

Protein folding

Answer 25

Protein to lowest energy conformation - stable.

Interact with other molecules - changes - crucial for function

Question 26

Incorrect folding of proteins leads to?

Answer 26

Amyloid fibrils accumulation.

Eg. Amylodogenic intermediate - ring shaped early aggregate - protofibrils - mature fibrils - lewy bodies

Question 27

Lewy bodies

Answer 27

Neurons - amyloid fibril accumulation - incorrect protein.

Faster produced than protein degradation pathway of protein unfolded protein response .

Parkinsons disease

Question 28

Leukaemia?

Answer 28

Ig light and heavy chains - incorrect - not secreted by cell - problem with immune response

Question 29

6 inclusion pathiogenesis. Name, site and disease associated

Answer 29

Levy bodies - neurons cyto - parkinsons
Huntingdon bodies - neuron nuclear - huntingtons disease
Hiramo bodies - neuron - neurodegenerative
Collins bodies - neuron - familial presenile genitris
Neurofibrillar tangles - neurons nuclear - alzhiemers, aging, dementia + other cerebral disorders