Lecture 5: Epithelial Tissues II (CAMs, Junctional Complexes)

Question 1

Cadherins

Answer 1

Major components in Ca2+ mediated adherens junctions (Ca2+ dependent); interact with actin via catenins

Question 2

Catenins

Answer 2

small proteins that link cytoplasmic end of cadherin with cytoplasmic actin

Question 3

Selectins

Answer 3

bind to carbohydrates; movement of leukocytes from blood to tissues

Question 4

Integrins

Answer 4

glycoproteins that are mainly involved in cell-extracellular matrix interactions (Ca2+ independent); link to actin filaments via connecting proteins

Question 5

Adherens

Answer 5

Molecular junctional complexes that anchor cells together and reinforce physical integrity of tissues and cells than make up the tissues (basolateral surfaces of epithelial cells)

Question 6

Occludens

Answer 6

Molecular junctional complexes that establish impermeable barrier between adjacent cells, especially epithelial cells, that prevents paracellular tarnsport and maintains concentration differences

Question 7

Gap Junctions

Answer 7

Molecular pores that enable cells to rapidly exchange ions and small molecules to help coordinate activities; composed of connexons

Question 8

Zonula

Answer 8

Adherens or Occludens; travel all the way around circumference of cell and link all neighboring cells to a central cell - “belt-like complexes”

Question 9

Macula

Answer 9

“Spot” or snap-like junction; Adherens variety; AKA desmosomes or hemidesmosomes

Question 10

Hemidesmosome

Answer 10

anchoring junction that anchors basal domain of epithelial cell to basal lamina; “hemi” because it links to basal lamina rather than another cell

Question 11

The basal lamina is associated with which type of collagen?

A. Type I
B. Type II
C. Type IV
D. Type VII

Answer 11

C. Type IV

Question 12

Which of the following types of CAMs is associated with the zonula occludens and desmosomes?

A. Cadherins
B. Integrins
C. Selectins
D. Immunoglobulin superfamily

Answer 12

A. Cadherins

Question 13

Desmocollins and desmogleins belong to which of the following groups of CAMs?

A. Cadherins
B. Integrins
C. Selectins
D. Immunoglobulin superfamily

Answer 13

A. Cadherins

Question 14

Which of the following serve as a major interface between cadherins that hold adjacent cells together and their actin cytoskeletons?

A. Proteoglycans
B. Catenins
C. Laminins
D. Keratins

Answer 14

B. Catenins

Question 15

The extracellular domains of which of the following bind to molecules in the extracellular matrix such as fibronectin and laminin?

A. Cadherins
B. Integrins
C. Selectins
D. Immunoglobulin superfamily

Answer 15

B. Integrins

Question 16

Which of the following are molecular complexes that anchor cells together and reinforce the physical integrity of tissues and the cells that make up tissues?

A. Zonula adherens
B. Zonula occludens
C. Hemidesmosomes
D. Connexons

Answer 16

A. Zonula adherens

Question 17

Which of the following molecular complexes primarily serve to prevent paracellular transport?

A. Zonula adherens
B. Zonula occludens
C. Hemidesmosomes
D. Connexons

Answer 17

B. Zonula occludens