Cell Surfaces, Junctional Complex

Question 1

What are the Cell Surfaces

Answer 1

1. Apical or mucosal surface
2. Basal Surface
3. Lateral Surface

Question 2

the connection between the neighboring Cells or the contact between the cell and extracellular Matrix.

Answer 2

Cell Junction

Question 3

Cell junction is also called the ______

Answer 3

membrane junction

Question 4

Cell junctions are classified into three functional groups: What are these

Answer 4

1. Occluding junctions
2. Communicating junctions
3. Anchoring junctions.

Question 5

These junctions prevent the movement of ions and molecules from one cell to another cell

Answer 5

Occluding Junction

Question 6

the intercellular occluding junction that prevents the passage of large molecules

Answer 6

Tight Junction

Question 7

Other term for tight junction

Answer 7

zonula occludens

Question 8

Proteins involved in the formation of tight junctions are classified into two types, what are these?

Answer 8

1. Tight junction membrane proteins or integral membrane proteins
2. Scaffold (framework or platform) proteins or peripheral membrane proteins or cytoplasmic plaque proteins.

Question 9

Give examples of scaffold (platform) proteins

Answer 9

as:
➢cingulin
➢symplekin
➢ ZO1, 2, 3

Question 10

Give examples of Tight junction membrane proteins or integral membrane proteins,

Answer 10

Occludin
Claudin
junctional adhesion molecules (JAMs)

Question 11

Give some Diseases caused by mutation of genes encoding proteins of tight junction:

Answer 11

1. Hereditary deafness
2. Ichthyosis (scaly skin)
3. Sclerosing cholangitis (inflammation of bile duct causing obstruction)
4. Hereditary hypomagnesemia (low level of magnesium in the blood)
5. Synovial sarcoma (soft tissue cancer)
6. Functions of tight junction are affected by some bacteria and viruses also

Question 12

junctions, which provide
strength to the cells by acting like mechanical attachments,

Answer 12

Anchoring Junctions

Question 13

anchoring junctions are classified into four types, what are these?

Answer 13

1. Actin filament attachment
   a. Adherens junction (cell to cell)
   b. Focal adhesion (cell to matrix)
2. Intermediate filament attachment
   a. Desmosome (cell to cell)
   b. Hemidesmosome (cell to matrix)

Question 14

What are the Junctional Complex

Answer 14

1. Tight junction (Zonula occludens)
2. Desmosomes (zonula adherens)
3. Hemidesmosomes (focal adhesions)

Question 15

The cell to cell junction, which connects the actin filaments of one cell to those of another cell.

The junction is held by transmembrane protein called _______.

Answer 15

Adherens junction

cadherins