Chapter 9 Flashcards
In what ways are ligand-receptor complexes similar to enzyme-substrate complex?
What are the four types of cell signaling?
Define signal transduction pathway
What are the three types of membrane receptors?
What is a G protein?
What is a second messenger?
Why are lipid hormones good for relaying signals across long distances?
Why does estrogen have a different effect in mammary vs uterine cells?
Describe the structure and function of RTKs
Ligand
signaling molecule that binds to a specific receptor protein
Receptor protein
Protein kinase
class of enzyme that adds phosphate groups from ATP to proteins
Phosphate is added to a free —OH on one of the three amino acids:
- Serine
- Threonine
- Tyrosine
Phosphatases
class of enzyme that removes phosphate groups from a protein
Intracellular receptors bind to _______ ligands
hydrophobic
__________ receptors bind to hydrophobic ligands
Intracellular
Cell-surface/membrane receptors bind to ________ ligands
hydrophilic
____________ receptors bind to hydrophilic ligands
Cell-surface/membrane
G protein is a protein that binds _____________.
guanosine triphosphate (GTP)
Steroid hormone receptors are an example of what type of receptor?
Intracellular receptor
What is the primary function of steroid hormone receptors?
regulation of gene expression
What are the three functional domains of steroid receptors?
- Hormone-binding domain
- DNA-binding domain
- Domain interacts with coactivators to affect level of gene transcription
Coactivator
T or F: Ligands can bind to any receptor
F: Specific ligands can only bind its complementary receptor
What is an example of direct contact?
Gap junctions
Example of paracrine signaling
Signaling between immune cells
What is an example of endocrine signaling
Hormones
What is an example of synaptic signaling?
Neurotransmitter
__________ is a primary mechanism for control of proteins
Phosphorylation (and dephosphorylation)
What is the structure of RTKs?
Single transmembrane domain
Extracellular ligand-binding domain
Intracellular kinase domain
What molecules can be used as signals in cell signaling?
Peptides, large proteins, amino acids, nucleotides, steroids or other lipids, dissolved gases or ions
Which types of cell signaling are important in early development?
Direct contact and paracrine signaling
Paracrine signaling
Signal releases from a cell has an effect on neighboring cells
Endocrine signaling
Signal molecule released from a cell travels through circulatory system to affect other cells throughout body
T or F: only animals use endocrine signaling.
F: both animals and plants use this endocrine signaling
______ signaling is often signaled by one cell type to a different cell type
Endocrine
Synaptic signaling
Nerve cells release the signal, which binds to receptors on nearby cells
What makes signal transduction pathways complex?
The same pathway can be activated but different receptors or the same signal can activate different cell types/responses
How does a coactivator affect mammary tissue?
When coactivator is lacking, gene expression is reduced
How does a coactivator affect uterine tissue?
When coactivator is present, gene expression is turned on
Describe the process of G protein coupled receptors
Ligand binds to G protein coupled receptor —> activation of receptor —> activates G protein —> activates enzyme
Dimerization
RTKs are brought closer together
Autophosphorylation
RTKs phosphorylate each other
Insulin
Hormone that helps maintain a constant blood glucose level
How does insulin lower blood glucose level?
Insulin response protein binds to RTK then binds to other proteins which activates glycogen synthase. This enzyme converts glucose to glycogen
