Cell Organisation

Question 1

What is the importance of cells coming together to form tissues

Answer 1

To specialise, withstand stress and gravity , also for better interaction

Question 2

Where on a eukaryotic cell diagram is ecm and actin filaments

Answer 2

Actin is inside cell forming cytoskeleton

ECM is outside of the cell

Question 3

Which types of intermediate filaments bind desmosomes for cell-cell interaction

Answer 3

Keratin intermediate filaments

Question 4

Which actin binding proteins are important for cellular movement, contraction and membrane/vesicular movement

Answer 4

Myosin 1 and 2 (2 is in muscle)

Question 5

Which structures are supported by actins

Answer 5

Microvilli

Question 6

Do all cells come together Eg for interaction and strength

Answer 6

No some are individuals Eg immune lymphocytes

Question 7

Explain the layers of gut

Answer 7

Epithelial lined microvilli (epithelial tissue of cells)

Then a connective tissue layer

Muscle tissue layer (with muscle cells)

Another connective tissue layer with a lot of ecm

Question 8

Why do we unlike plants need tissues and cell adhesion strength

Answer 8

We don’t have a plant cell wall to withstand mechanical stress

Question 9

Give 2 examples of connective tissue/ecm

Answer 9

Cartilage and bone

Question 10

Give the name of the ecm usually under epithelial tissue

Answer 10

Basal lamina

Question 11

How does epithelial,muscle and nervous tissue differ from connective tissue

Answer 11

Higher cell-cell contact, less ecm

Connective tissue like cartilage has a lot of ecm and less cells like fibroblasts

Question 12

How do cells communicate in high ecm connective tissues if spaced out

Answer 12

Via the ecm

Question 13

Give 2 examples of where epithelial tissue is

Answer 13

Microvilli in gut

Epidermis of skin (High cell cell contact)

Question 14

What links cells for mechanical force and signalling and how

Answer 14

Cell junctions

They interact with cytoskeleton either actin or if

Question 15

What is basal lamina for which attaches via actin to cells

Answer 15

Barrier to stress and also withstand gravity

Question 16

Which 2 ways can cells communicate in epi/ other muscle or nervous tissues

Answer 16

Directly cell cell via junctions or indirectly via ecm / Basal lamina

Question 17

Cells are polarised. Where do molecules made my cell go to from er

Answer 17

Baso lateral membrane

Question 18

What are the 4 epithelial cell types

Answer 18

Columnar (long)

Cuboidal

Squamous (flat)

Stratified (stacked)

Question 19

What are proteins which link cell junctions/ or integrons etc to cytoskeleton called

Answer 19

Ic Adaptor proteins

Question 20

What junctions use Cadherins (adhesion molecules)

Answer 20

Adheren junctions

Question 21

Which linker proteins bind Cadherin with actin filaments in adheren junctions

Answer 21

Catenins

Question 22

What is cadherin in epithelial tissue called

Answer 22

E cadherin

Question 23

What makes cadherins flexible in response to calcium

Answer 23

Hinge region

Question 24

What is the term to say cadherins Eg e cadherins only bind other e cadherins

Answer 24

Homophillic

Question 25

What happens when ca becomes present to cadherins

Answer 25

They stop being rigid and close to cell membrane Stick out via hinge region and can bind other e cadherins

Question 26

How does catenin make contact with actin and stabilise

Answer 26

Vinculin

Question 27

Which small gtpases allow cell signalling eg protrusion/cell motility during cadherin junctions

Answer 27

RAC gtpase

Question 28

What is rho gtpase for

Answer 28

Further stability and gravity withstanding and also cell signalling

Question 29

Is cadherin reduced in cancers or increased

Answer 29

Reduced. Causing metastasis because lack of cell adhesion

Question 30

How are desmosome junctions different to adheren junctions

Answer 30

Interact with intermediate filaments instead of actin

Question 31

What are the 2 non classical cadherin proteins in desmosome junctions

Answer 31

Desmoglein Desmocollin

Question 32

What linker/adapter holds IF to the desmoglein/desmocollins

Answer 32

Desmoplakin

Question 33

What are tight junctions for

Answer 33

Cell polarity Diff apical to baso lateral Form a selective permeability barrier to molecules like glucose receptors which will differ apical and basal side

Question 34

Give an example of polarisation using glucose via tight junctions

Answer 34

Diff glucose transporters at top Eg glucose na transporter apical side, then a glut on basal side for reabsorption

Question 35

Which junctions bind IF to ecm to hold cell matrix interaction

Answer 35

Hemidesmosomes

Question 36

Which 2 channels are in gap junctions

Answer 36

Connexins and innexins

Question 37

What is allowed through gap junctions

Answer 37

Small water soluble molecules Not proteins

Question 38

Give an example of a molecule which can close gap junctions to reduce communication in cells

Answer 38

Dopamine in neurones