CELL 4 Flashcards
what is signal transduction
sequence of events between binding of messenger to receptor and cellular response
what are chemical messengers
- form of indirect intercellular communication
2. ligand that binds reversibly to receptor
what does reversible binding mean
ligand + receptor can come together and come apart
what happens when one cell releases chemical messenger
binds to receptor on another cell
what does binding of chemical messenger to receptor result in
cellular response
what are 2 types of chemical messengers
- lipid soluble
2. lipid insoluble
what happens if messenger lipid soluble
can pass through PM to bind to intracellular receptor
what happens if messenger is lipid insoluble
cannot pass through PM to bind to intracellular receptor
where can receptors be located
- PM of cell (mem bound)
2.cytoplasm (intracellular)
3 nucleus (inracellular)
what do lipid soluble chemical messengers bind to
- mem bound receptors
2. intracellular receptors
what do lipid insoluble chemical messengers bind to
mem bound receptors
INTRACELLULAR RECEPTORS what is mechanism of lipid soluble messengers if receptor is in cyto
- diffuse from capillaries to interstitial fluid
- diffuse across PM
- messenger binds to receptor in cyto
- messenger-receptor complex moves into nucleus through nuclear pores
- messenger receptor complex functions as a transcription factor
INTRACELLULAR RECEPTORS what is the mechanism of lipid soluble messengers if receptor is in nucleus
- diffuse from capillaries to interstitial fluid
- diffuse across PM
- diffuse across nuclear mem
- binds to receptor in nucleus
- messenger receptor complex acts as transcription factor
MEM BOUND RECEPTORS what surface are of PM are mem bound receptors located on
extracellular
MEM BOUND RECEPTORS what are paracrine compounds
compounds released by one cell + act on neighbouring cell
MEM BOUND RECEPTORS what are autocrine compounds
compounds released by one cell + act on same cell
what is first messenger
extracellular messenger
what is second messenger
- molecule that enters cyto as a result of binding of first messenger
- molecule generated in cyto as a result of binding of first messenger
INTRACELLULAR RECEPTORS how do lipid soluble chemical messengers produce effect in cell
act as transcription factors
INTRACELLULAR RECEPTORS what is the function of transcription factors
- bind to response element (DNA sequence at beginning of gene)
- activate or deactivate gene
INTRACELLULAR RECEPTORS what does activation of gene mean
mRNA transcription
INTRACELLULAR RECEPTORS what does deactivation of gene mean
no mRNA transcription
INTRACELLULAR RECEPTORS what happens as a result of transcription being affected
- alter rate of translation
2. alter rate of protein synthesis
INTRACELLULAR RECEPTORS what does protein synthesis lead to
cellular response
what is a protein kinase
enzyme that phosphorylates other proteins
what happens when protein is phosphorylated
- change in conformation
2. change in activity