Hormone Signaling Pathways

Question 1

Hormones

Answer 1

Messenger molecules

Syn and secreted by endocrine cells, released into blood stream

Bind specific receptors and results in activation of signal transduction and/or alteration in gene expressing that lead to cell type-specific response

Question 2

Steps in Cell Signaling

Answer 2

Biosyn
Storage
Secretion 
Transport to target tissue/cells
Recognition and binding to receptors
Activation of signal transduction pathway (on switch) 
Amplification and relay of signal 
Cellular response 
Degradation (switch off)

Question 3

Endocrine Signaling

Answer 3

Signaling molecule released by a cell distant from the target cell and transported via the bloodstream to target cell

Question 4

Paracrine Signaling

Answer 4

Signaling molecule released by one cell type and diffuses to a neighboring target cell of a different cell type

Question 5

Autocrine Signaling

Answer 5

Signaling molecule acts on the same cell type as the secreting cells themselves

Question 6

Juxtacrine Signaling

Answer 6

Signaling molecule stays attached to the secreting cell and binds to a receptor on an adjacent target cell

Question 7

Hydrophilic Hormone Signaling

Answer 7

Can’t penetrate the plasma membrane, and must interact with specific receptor at the cell surface

Signaling molecule-receptor complex initiate production of second messenger

G protein coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs)

Question 8

Lipophilic Hormone Signaling

Answer 8

Passively diffuse thru the plasma membrane

Bing to receptor proteins within the cell

Hormone-receptor complex acts as a transcription factor

Cytoplasmic and nuclear receptors and both regulate the transcription of specific genes

Question 9

Cytoplasmic Receptors

Answer 9

Exist in an inactive complex with HSP 90

Upon binding HSP 90 dissociates

Hormone-receptor complex translocates to nucleus and bond DNA sequence called the hormone response element (HRE) in the promoter region of the specific gene

Question 10

Nuclear Receptor

Answer 10

Already present in nucleus bound t DNA

The hormone allows for interaction with additional proteins and activates the complex

Question 11

Hydrophilic and Lipophilic Medications

Answer 11

Hydro: Have short half lives (sec to min)

Lipo: have long half lives (hours to days)