ligand

receptor protein

receptor protein

(where is it?)

the molecule to which a receptor binds

on plasma membrane or within the cell

direct contact

paracrine signaling

endocrine signaling

synaptic signaling

signal released from a cell has an effect on neighboring cells.

(farting)

hormones released from a cell affect other cells throughout the body.

(distance signaling)

Different cell types can ____ ____ to the same signal

Different cell types can ______ ____ to different signals

respond differently

respond similarly

cell surface receptor

aka...

located on the plasma membrane to bind a ligand outside the cell.

membrane receptor

channel linked receptors

enzymatic receptors

G protein-coupled receptors

Steroid Hormones:

Have a ____, _____ structure

Can cross the ___ ___ to a ____ ____

Usually affect the regulation of _____ _____

nonpolar, lipid soluble

plasma membrane to a steroid receptor

gene expression (inhibitor prevents receptor from binding to DNA until hormone is present)

hormone binding domain

DNA binding domain

domain that interacts with coactivators to affect gene expression

hormone/gene expression process:

• hormones cross ___ ___ and bind to ____ ____
• __ __ alters receptor conformation so it no longer binds to _____
• hormone-receptor complex moves to ____
• hormone receptor complex binds to _____, turning ____ on or off.
• Cellular response is a change in ____ _____

• plasma membrane, cytoplasmic receptors
• hormone binding, inhibitor
• the nucleus
• DNA, transcription
• gene expression

receptor tyrosine kinase:

• ____ receptor
• when ligand bound, receptor activated by _____ and _____
• activated receptor adds a ___ to tyrosine on a ___ ___
• well known example:

• membrane
• dimerization and autophosphorylation
• phosphate, response protein
• insulin receptor

insulin signaling process:

• insulin binds to the ___ ____ of insulin receptor
• ___ ____ phosphorylate eachother allowing __ ___ ___ to be activated
• phosphorylated insulin response proteins activate ___ ____
• glycogen synthase converts __ to __

• alpha subunit
• beta subuni, insulin response protein
• glycogen synthase
• glucose to glycogen

kinase cascade

-amplifies b/c ...

a series of protein kinases that activate each other in succession

a few signal molecules can cause a large cell response

MAP cascade process:

• receptor bound proteins activate Ras by exchanging ___ for ___
• Ras activates first kinase: ____
• which activates the 2nd kinase: ___
• which activastes map kinases: __
• which activates proteins to produce a ___ ___, including __ __ that alter gene expression

• Ras , GDP for GTP
• Raf
• MEK
• ERK
• cellular response, transcription factors

G protein is a ___ that is turned on by ___

G protein then activates an ___, which then activates a ___ ____.

switch, the receptor

effector protein (usually an enzyme), second messenger

cells can recognize each other by ___ ___

communication junctions

(in animals)

(in plants)

permit small molecules to pass b/t cells

gap junctions

plasmodesmata