more on the endomembrane

Question 1

extracellular vesicles

Answer 1

(EVs) are membrane-contained vesicles released in an evolutionally conserved manner by cells ranging from organisms such as prokaryotes to higher eukaryotes and plants

Question 2

where are these extracellular transport vesicles released from

Answer 2

cells

Question 3

where in the body are extracellular transport vesicle found

Answer 3

body fluids: urine, blood, fluid found around the brain and spinal

Question 4

2 kinds of extracellular vesicles

Answer 4

micro vesicles and exosomes

Question 5

role of exosomes and microvesicles

Answer 5

-immunology
-in blood
-central never system
0in bone

Question 6

role of exosomes and micro vesicles in the blood

Answer 6

stimulation of coagulation, blood vessel formation and thrombosis

Question 7

role of exosomes and micro vesicles win central nervous system

Answer 7

integration of neurones and various glial cell types, control of synaptic function, neuronal plasticity, neuronal glial communication and myelination

Question 8

role of exosomes and micro vesicles in bones

Answer 8

modifying enzyme activity

Question 9

extracellular vesicles can..

Answer 9

spread cancer

Question 10

how can extracellular vesicles cause cancer

Answer 10

release content to extracellular space, due to the release of RNA and proteins causing a change in expression patterns within the nucleus

Question 11

micro vesicles (ectosomes) size

Answer 11

500nm-1000nm diameter

Question 12

microvesicles formation

Answer 12

occurs at donor plasma membrane and contains transfer proteins, mRNA and miRNAs. Uptake occurs via fusion with plasma membrane

Question 13

exosome size

Answer 13

40-100nm

Question 14

exosome formation

Answer 14

formed at early endosomes, released from late endosomes. Contain transfer proteins, mRNA and miRNA ( controls protein expression). Uptake via endocytosis or fusion with recipient plasma membrane

Question 15

what are inside extracellular vesicles

Answer 15

transfer proteins, mRNA and miRNA

Question 16

exosomes are non cytotoxic and therefore

Answer 16

well tolerated.

Question 17

transfer of information using extracellular vesicles

Answer 17

RNAs and proteins are derived from donor cells and the exosomes protect their content against degradation and targets specific tissue.

Question 18

extracellular vesicles can be

Answer 18

purified from blood and other fluids

Question 19

peroxisomes

Answer 19

single membrane bound organelles that contain many enzymes- major site of oxygen utilisation and involved in lipid metabolism

Question 20

mamalian peroxisomes contain … diff enzymes and over… peroxins

Answer 20

50 different enzymes and over 20 peroxides that mediate import

Question 21

detoxification in peroxisomes generates

Answer 21

hydrogen peroxide which is degraded by catalase

Question 22

hydrogen peroxide is degraded by

Answer 22

catalase

Question 23

lipid droplets

Answer 23

fat storage droplets–> vary in size and are enclosed by a monolayer

Question 24

when in starvation mode

Answer 24

the lipid droplet is broken down

Question 25

where are lipid droplets produced

Answer 25

smooth endoplasmic reticulum

Question 26

process of forming a lipid droplet

Answer 26

1) fatty acids cholesterol build up in the inner membrane of the SER 2 proteins attach to the outside of this area and a circular organelle is formed 3) Fat-acid-bdining protein (FABP) make gatty acid water soluble (thy shield the fatty acid by binding it in a hydrophobic pocket

Question 27

FABP

Answer 27

fat-acid binding protein --> used to make fatty acids water soluble --> needed for burning fat

Question 28

how much of the protein in liver cells do FABP make up

Answer 28

5%

Question 29

peroxisome genesis

Answer 29

part of the ER forms a precursor vesicle with a few cytosolic proteins and lipid. The growth by uptake of cytosolic proteins and lipid to form a peroxisome. . This will grow and fission will occur to form two peroxisomes

Question 30

important roles of peroxisomes

Answer 30

biosynthesis of cholesterol and breakdown of very long chain fatty acids (beta-oxidation)

Question 31

in plants what converts fats to sugar

Answer 31

glyoxysomes found close to lipid droplets

Question 32

nucleomorph

Answer 32

Nucleomorphs are small, vestigial eukaryotic nuclei found between the inner and outer pairs of membranes in certain plastids. They are thought to be vestiges of primitive red and green algal nuclei that were engulfed by a larger eukaryote.

Question 33

where are nucleomorphs found

Answer 33

in some algae

Question 34

nucleomorph simple

Answer 34

a DNA containing relict of an engulfed eukaryote

Question 35

definition of cytoskeleton

Answer 35

cytoskeleton consist of filamentous bio-polymers (microtubules, F-actin and intermediate filaments) and oaf associated proteins that modulate the activity, dynamics and organisation of the cytoskeleton (actin binding or microtubule binding proteins, such as molecular motors)

Question 36

filamentous bio-polymers in the cytoskeleton

Answer 36

microtubules, F-actin, intermediate filaments)

Question 37

proteins associated with the cytoskeleton

Answer 37

actin binding or microtubule binding proteins, such as molecular motors

Question 38

eukaryotic cytoskeleton provides

Answer 38

tracks that link the regions of the cell

Question 39

skeleton

Answer 39

- -> connects all parts of the cell - -> supports motility - -> helps spatial organisation

Question 40

F actin location

Answer 40

found closest to the membrane

Question 41

microtubules location

Answer 41

spans from the centrosome to the outside of the cell

Question 42

intermediate filaments

Answer 42

found all around the cell

Question 43

three classes of filaments that make up the cytoskeleton

Answer 43

f actin, microtubules, intermediate filaments

Question 44

f actin also known as

Answer 44

microfilaments

Question 45

F actin

Answer 45

7-9nm --> short range transport and cell migration

Question 46

Microtubule

Answer 46

25nm --> long range transport and chromosome inheritance (mites, meioses)

Question 47

intermediate filaments

Answer 47

10nm --> mechanical strength

Question 48

cytoskeleton as well as proving tracks for intracellular trafficking, also provides..

Answer 48

stability for the cell e.g. extreme example: membrane cytoskeleton of red blood cells make them stiff and strong

Question 49

structure of F actin

Answer 49

- made up of G actin monomers - f actin is made up of 2 photo filaments - actin exists as monomers and polymers - F actin will release G actin - cell switches between g and f actin

Question 50

most actin in the cell is

Answer 50

G actin

Question 51

how many different actin binding proteins ar known

Answer 51

160

Question 52

what do actin binding proteins d

Answer 52

they modify actin organisation

Question 53

actin forms

Answer 53

cellular protrusion e.g. sterocilia on hair cells in the inner ear e.g. microvilli on an intestine epithelium

Question 54

examples of different formations of actin

Answer 54

stabilising, capping, depolymerising, cross-linking, severing, moving, bundling

Question 55

ordered bundling

Answer 55

microvilli, sterocilia

Question 56

dynamic crosslinking

Answer 56

stress-fibres and muscle

Question 57

cross linking

Answer 57

network formation

Question 58

myosin is used in

Answer 58

actin in a 'moving' formation

Question 59

firkin, alpha-actinic is used in

Answer 59

bundling and stabilising

Question 60

filamin, spectrum are used in

Answer 60

sequestering/recycling and branching