Cell-Cell Communication 1 Flashcards
What is a Ligand?
Substance that forms a complex with a biomolecule to serve a biological purpose.
What are Extracellular Signal Molecules?
Ligands that can act over short or long distances. Also called First Messengers.
What does a Neurotransmitter do?
Transmits signals across a chemical synapse- from neuron to neuron, neuron to muscle cell, or neuron to gland cell.
What is a Receptor?
A protein molecule that receives chemical signals from outside the cell.
Where are receptors typically located?
On the cell surface, or inside the cell- nucleus or cytoplasm.
T/F: On the cell surface, the signal molecules are hydrophilic.
True.
T/F: Inside of the cell contains hydrophobic signal molecules.
True.
What are the 3 major types of cell surface receptors that we discussed?
- Ligand-Gated Ion Channel Receptors
- G-Protein Coupled Receptors
- Enzyme Coupled Receptors –> RTK
What are Second Messengers?
Intracellular signaling molecules generated in large amounts in response to receptor activation.
T/F: There are many second-messenger systems in animal cells.
False; few.
Which second messenger(s) are located in the cytoplasm and are hydrophilic?
IP3, cAMP, Ca 2+
Which second messenger(s) are located in the plasma membrane and are hydrophobic?
DAG
What is a Molecular Switch?
Proteins that help relay the signal into the cell by either generating second messengers, activating the next signaling or effector protein in the pathway.
When they receive a signal, molecular switchers switch from an active state to an inactive state until another process switches them off.
False; inactive to active.
What are the most important molecular switchers?
Protein Kinase ( Serine/ Threonine Kinases & Tyrosine Kinases), Protein Phosphatase, GTP- Binding protein.
