cytokines

Question 1

Advantages & disadvantages of contact dependent cell communication

Answer 1

Occurs between cells that are in direct contact with each other

Allows for precise targeting of signaling molecules to specific cells
Enables cells to receive & respond to signals quickly

Limited by physical proximity
Slow transmission across organ

Question 2

Advantages & disadvantages of synaptic cell communication

Answer 2

Occurs between neurons & other cells

Fast & localised signaling over long distances

Limited to certain cell types
Limited specificity

Question 3

Advantages & disadvantages of paracrine cell communication

Answer 3

Occurs when signaling molecules are released into extracellular fluid & diffuse to nearby cells

Allows for widespread effects on multiple cells
Allows for fine-tuning of signaling responses by adjusting concentration of signaling molecules

May result in non-specific signaling
May be affected by diffusion barriers

Question 4

Advantages & disadvantages of endocrine cell communication

Answer 4

Occurs when signaling molecules are released into bloodstream & travel to distant cells

Allows for widespread effects on multiple cells & organs
Enables long-term signaling & regulation of physiological processes

May take longer for signaling molecules to reach target cells
May be affected by metabolism & clearance

Question 5

How is signal specificity achieved

Answer 5

Complementary shape
Chemical specificity
Spatial organisation
Signal amplification

Question 6

Characteristics of lipid bilayer

Answer 6

Cell membrane is mosaic of different proteins imbedded in fluid matrix of lipid bilayer
Membranes held together by hydrophobic interactions
Hydrophilic heads & hydrophobic tails
Fluidity is temperature dependent

Question 7

What are lipid rafts

Answer 7

Interactions between lipids generate formation of lipid rafts
More ordered & tightly packed than surrounding bilayer but float freely within membrane bilayer
Important for cell signaling

Question 8

Structure & function of cytokines

Answer 8

Small glycoproteins released by cells
All cells can produce cytokines

Mediate immune response, especially inflammation

Signal through specific receptors on surface of target cells

Question 9

What are the effects of cytokines

Answer 9

Pleiotropy
Same cytokine can bind to multiple cells & each cell will have different reaction/produce different outcome

Redundancy
2 or more cytokines have similar effects on cells

Synergy
Combined effect of cytokines can be greater compared to each cytokine alone

Antagonism
1 cytokine may inhibit activity of another

Cascade activation
1 cytokine may induce cascade of cytokine expression involving multiple cells