Cell Organisation Flashcards
What is the importance of cells coming together to form tissues
To specialise, withstand stress and gravity , also for better interaction
Where on a eukaryotic cell diagram is ecm and actin filaments
Actin is inside cell forming cytoskeleton
ECM is outside of the cell
Which types of intermediate filaments bind desmosomes for cell-cell interaction
Keratin intermediate filaments
Which actin binding proteins are important for cellular movement, contraction and membrane/vesicular movement
Myosin 1 and 2 (2 is in muscle)
Which structures are supported by actins
Microvilli
Do all cells come together Eg for interaction and strength
No some are individuals Eg immune lymphocytes
Explain the layers of gut
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
Why do we unlike plants need tissues and cell adhesion strength
We don’t have a plant cell wall to withstand mechanical stress
Give 2 examples of connective tissue/ecm
Cartilage and bone
Give the name of the ecm usually under epithelial tissue
Basal lamina
How does epithelial,muscle and nervous tissue differ from connective tissue
Higher cell-cell contact, less ecm
Connective tissue like cartilage has a lot of ecm and less cells like fibroblasts
How do cells communicate in high ecm connective tissues if spaced out
Via the ecm
Give 2 examples of where epithelial tissue is
Microvilli in gut
Epidermis of skin (High cell cell contact)
What links cells for mechanical force and signalling and how
Cell junctions
They interact with cytoskeleton either actin or if
What is basal lamina for which attaches via actin to cells
Barrier to stress and also withstand gravity
Which 2 ways can cells communicate in epi/ other muscle or nervous tissues
Directly cell cell via junctions or indirectly via ecm / Basal lamina
Cells are polarised. Where do molecules made my cell go to from er
Baso lateral membrane
What are the 4 epithelial cell types
Columnar (long)
Cuboidal
Squamous (flat)
Stratified (stacked)
What are proteins which link cell junctions/ or integrons etc to cytoskeleton called
Ic Adaptor proteins
What junctions use Cadherins (adhesion molecules)
Adheren junctions
Which linker proteins bind Cadherin with actin filaments in adheren junctions
Catenins
What is cadherin in epithelial tissue called
E cadherin
What makes cadherins flexible in response to calcium
Hinge region
What is the term to say cadherins Eg e cadherins only bind other e cadherins
Homophillic
What happens when ca becomes present to cadherins
They stop being rigid and close to cell membrane
Stick out via hinge region and can bind other e cadherins
How does catenin make contact with actin and stabilise
Vinculin
Which small gtpases allow cell signalling eg protrusion/cell motility during cadherin junctions
RAC gtpase
What is rho gtpase for
Further stability and gravity withstanding and also cell signalling
Is cadherin reduced in cancers or increased
Reduced. Causing metastasis because lack of cell adhesion
How are desmosome junctions different to adheren junctions
Interact with intermediate filaments instead of actin
What are the 2 non classical cadherin proteins in desmosome junctions
Desmoglein
Desmocollin
What linker/adapter holds IF to the desmoglein/desmocollins
Desmoplakin
What are tight junctions for
Cell polarity Diff apical to baso lateral
Form a selective permeability barrier to molecules like glucose receptors which will differ apical and basal side
Give an example of polarisation using glucose via tight junctions
Diff glucose transporters at top Eg glucose na transporter apical side, then a glut on basal side for reabsorption
Which junctions bind IF to ecm to hold cell matrix interaction
Hemidesmosomes
Which 2 channels are in gap junctions
Connexins and innexins
What is allowed through gap junctions
Small water soluble molecules
Not proteins
Give an example of a molecule which can close gap junctions to reduce communication in cells
Dopamine in neurones
