Tissue Architecture

Question 1

What is collagen’s main function?

Answer 1

Main structural protein in ECM/ connective tissue and basal lamina

Question 2

On what end of the actin filament does growth occur with ATP bound actin?

Answer 2

+ end

Question 3

What happens to collagen in lumen of ER and Golgi apparatus?

Answer 3

self-assembly of the tropocollagen molecule:

disulfide bond formation in C-terminal extensions –> triple helix formation

Question 4

On what end of the actin filament are there more ADP-bound actin; where shrinkage occurs?

Answer 4

• end

Question 5

What do proteoglycans do?

Answer 5

in ECM and connective tissue

combo of this and collagen forms cartilage

Question 6

What ehler-danlos mutations are autosomal dominant?

Answer 6

mutations to genes for collagen itself

Question 7

Where are intermediate filaments often anchored to PM?

Answer 7

at cell-cell junctions

Question 8

What form are intermediate filaments in?

Answer 8

coiled-coil dimer (can make tetramers)

Question 9

In scurvy, what enzymes are affected?

What molecule does this affect?

Answer 9

Prolyl and lysyl oxidase need iron and ascorbate to function –> don’t have w/out vit c
screws up collagen synthesis

Question 10

What cell functions are microtubules used for?

Answer 10

form mitotic spindle = important for mitosis
cilia
flagella

Question 11

What is a tubulin heterodimer made of?

Answer 11

alpha and beta tubulin

Question 12

What happens to collagen outside of the cell?

Answer 12

cleavage of propeptides –> remove N and C terminal extentions –> collagen

Question 13

What proteins are in the basal lamina?

Answer 13

laminin
collagen IV
fibronectin

Question 14

What mesh-like structure do intermediate filaments make up?

Answer 14

nuclear lamina

Question 15

What does elastin do?

Answer 15

elastic protein in connective tissues

allows tissues to regain shape after stretchin

Question 16

What cell function(s) are actin filaments essential for?

Answer 16

movements: locomotion, phagocytosis, cell division, contraction, etc

Question 17

What is F-actin a polymer of?

Answer 17

G-actin

Question 18

What are the three types of cytoskeletal filaments you should know?

Answer 18

intermediate filaments
Microtubules
microfilaments

Question 19

How is collagen structured?

Answer 19

trimeric:

forms triple helix

Question 20

What happens to collagen in the Rough ER?

Answer 20

synthesis of preprocollagen –> procollagen inserted into ER lumen

Question 21

How do microtubules grow?

Answer 21

at plus ends from gamma-tubulin ring complexes of the centrosome

Question 22

What cytoskeleton filaments are unstable bc they grow and shrink a lot, but are stabilized by association w/ other proteins?

Answer 22

microfilaments (actin)

Question 23

What does fibronectin do?

Answer 23

linker molecule in ECM; anchors cells to collagen or proteoglycan substrates

Question 24

What filament has great tensile strength?

Answer 24

intermediate filaments

Question 25

What types of collagen are deformed in Ehler-Danlos?

Answer 25

I, III, V

Question 26

How does laminin exist?

What does it do?

Answer 26

as a heterotrimer
T shaped w/ alpha, beta, and gamma parts
part of basal lamina?

Question 27

What ehler-danlos mutations are autosomal recessive?

Answer 27

mutations to enzymes used in synthesis

Question 28

What are anchoring junctions?

Answer 28

cell-cell or cell-matrix

Question 29

Where are extracellular matrix and basal lamina components produced?

Answer 29

in cell and then secreted out

Question 30

What happens to collagen in the ER lumen?

Answer 30

proline and lysine get hydroxylated –> selected hydroxylysine residues get glycosylated

Question 31

What happens to collagen in the secretory vesicle?

Answer 31

procollagen prepared for secretion from cell

Question 32

what drug binds and stabilizes microtubules?

Answer 32

taxol