Cell biology - Extracellular matrix

Question 1

in most connective tissue what is ECM produced by

a. osteoblasts
b. fibroblasts

Answer 1

b.fibroblasts

Question 2

what produce hydroxyapatite

a. fibroblasts
b. osteoblasts

Answer 2

b.osteoblasts

Question 3

lysyl hydroxylase adds OH to lysines, prolyl hydroxylase adds OH to prolines
what do these processes require

a. H2o and vit c
b. iron and vit K
c. iron and vit C

Answer 3

c.iron and vit C

Question 4

lysyl hydroxylase forms bonds between how many collagen molecules to form procollagen

a. 2
b. 4
c. 6
d. 3

Answer 4

d.3

Question 5

which enzymes cleave propeptides to form tropocollagen

a. lysyl hydroxylase
b. collagen peptidases
c. lysyl oxidase

Answer 5

b.collagen peptidases

Question 6

what does lysyl oxidase do?

a. bond forming between 3 collagen molecules
b. cleaving propeptides
c. slef assembly of tropocollagen to fibrils

Answer 6

c.slef assembly of tropocollagen to fibrils

Question 7

ehlers danlos syndrome is caused by a mutation in the collagen / which enzyme

a. lysyl hydroxylase
b. collagen peptidases
c. lysyl oxidase

Answer 7

b.collagen peptidases

Question 8

what is defected in epidermolysis bullosa

a. intercellular connections
b. skin to ECM

Answer 8

b. skin to ECM

Question 9

mutations to laminin genes and in collagen 17A1 causes what

a. progeria
b. marfans
c. ehlers danlos
d. junctional epidermolysis bullosa

Answer 9

d.junctional epidermolysis bullosa

Question 10

which of these has significant role in scar formation

a. osteoblasts
b. chondrocytes
c. fibroblasts

Answer 10

c. fibroblasts

Question 11

what is caused by mutations in the gene for type IV collagen crucial for basement membranes in the kidney, ear and inner eye

a. progeria
b. marfans
c. ehlers danlos
d. junctional epidermolysis bullosa
e. alport syndrome

Answer 11

e.alport syndrome

Question 12

what is the classic symptom of alport syndrome

a. peeling skin
b. cataracts
c. end stage renal disease
d. hearing loss
e. haematuria

Answer 12

e. haematuria

Question 13

what do matric metalloproteinases do?

a. build ECM
b. degrade ECM

Answer 13

b.degrade ECM

critical for macrophage invasion during infection

Question 14

what is applied as a treatment for diabetic ulcers

a. collagen
b. keratin
c. elastin

Answer 14

a.collagen

Question 15

what do extracellular collagen - fibronectin bind to the actin cytoskeleton via

a. elastin
b. integrins
c. basal lamina

Answer 15

b.integrins

Question 16

which of these substances is made up of proteins with covalently linked carbs

a. glycoproteins
b. proteoglycan

Answer 16

a.glycoproteins

Question 17

which of these substances is made up of extra cellular proteins linked to complex -ve charged carbs (GAGs) , WITH SUGAR AS THE PREDOMINANT ELEMENT

a. glycoproteins
b. proteoglycan

Answer 17

b.proteoglycan

Question 18

cell surface proteins eg blood group antigens are examples of..

a. glycoproteins
b. proteoglycan

Answer 18

a.glycoproteins

Question 19

vit C defficiency causing a reduced collagen turnover leads to which condition

a. scurvy
b. metastaic breast cancer
c. marfans
d. ehlers danlos syndrome
e. marfans

Answer 19

a. scurvy

Question 20

epithelial cells dettaching from the basal lamina , degrading the ECM and migrating to other tissues causes which condition

a. scurvy
b. metastaic breast cancer
c. marfans
d. ehlers danlos syndrome
e. marfans

Answer 20

b.metastaic breast cancer

Question 21

a mutation in fibrillin leads to which condition

a. scurvy
b. metastaic breast cancer
c. marfans
d. ehlers danlos syndrome
e. marfans

Answer 21

c.marfans

Question 22

the basal lamina is a specialised ECM of laminin and which type of collagen

a. I
b. II
c. III
d. IV

Answer 22

d.IV

Question 23

laminin plays a similar role to what in CT

a. fibronectin
b. integrins
c. actin

Answer 23

a.fibronectin

Question 24

defects in what structure can cause blistering diseases

a. desmosomes
b. tight junctions
c. gap junctions
d. hemidesmosomes

Answer 24

d.hemidesmosomes