why is cell to cell communication critical?
critical for the function and survival, responsible for growth, development, involves sending and receiving to a cell
what is direct contact
cell to cell communication, directly between cytoplasm of two adjacent cell via channels
animals are gap junctions while plants are plasmodesmata
what is local signaling? what are the 3 types?
paracrine- signaling cell and releasing chemical messages through short distance (extracellular fluid)
synaptic- animal nervous system, secrets neurotransmitters, diffuse across cleft and bind to receptors
autocrine- cell signaling to itself, bind to receptors on the same cell, allows for regulation either positive or negative
what is long distance signaling
use long distance signaling molecules called hormones
plants release it in plants vascular tissue like xylem and phloem or through air
animals release it into the circulatory system
where does cell signaling begin?
interaction between ligand (chemical messenger) and receptor (proteins that recognize and bind to specific ligands)
what are the 3 surface receptors domain
hydrophilic
ligand binding- interacts with ligand
transmembrane- hydrophobic region that spans plasma membrane
intracellular domain- inside the cell that transmit signal
what are the 2 domains for intracellular receptors and where can they be found in?
found in cytoplasm and nucleus, hydrophobic, function as transcription factor
1) interact with ligand
2) DNA binding domain that interacts with target genes
what are the 3 stages of cell to cell signaling
reception, transduction, response
what does the 3 stages of cell to cell signaling do in intracellular response
reception- ligand diffuse across plasma membrane and bind to intracellular receptors
transduction- cause DNA binding domain of receptor to change and activate
response- ligand receptor complex bind to control regions of the genes and turn its function on or off
3 stages for cell surface receptors
reception- ligand bind to specific receptor of target cell
transduction- bind to receptors and it activates and initiate signaling cascade
response`- final molecule in signaling pathway converts the signal to a response that alters cellular process
definition of protein kinase
relay and amplify the message by transferring phosphate group from ATP to a protein
definition of protein phosphates
enzymes that remove phosphate groups from proteins and returns the protein back to baseline, regulate protein kinase activity, and shut off pathways
what molecule activates protein kinase
cyclic AMP
what are GPCRs
G coupled protein, important in animal sensory systems, activates G proteins (inactive until ligand binding is extracellular side)
- cause conformational change
- receptor activates G proteins by causing GDP to release and GTP to bind
what produces second messenger
effectors
what does second messenger activate
protein kinase and cellular response
