Principles Of Cell Signalling Flashcards
What are signal molecules that can pass the plasma membrane called?
They bind intracellular receptors.
What are signal molecules that cannot pass the plasma membrane called?
They bind transmembrane receptors.
Name the three major types of transmembrane receptors.
- Ion-channel-coupled receptors
- G-protein coupled receptors
- Enzyme-coupled receptors
What type of receptor does acetylcholine bind to?
- Nicotinic ACh receptor
- Muscarinic ACh receptor
What is paracrine signaling?
Signaling that occurs via a short distance.
What is neuronal signaling?
Signaling that occurs in the synaptic cleft.
What is endocrine signaling?
Signaling via the bloodstream that is remote.
What type of signaling occurs with no signal release?
Contact signaling.
What is the effect of remote signals in endocrine signaling?
They act over the whole body via the bloodstream to target cells.
What are neurotransmitters?
Signals released by neuronal cells.
What is the typical distance for paracrine signaling?
Diffusion of signals over a short distance to target neighboring cells.
What happens if there is no receptor for a signal?
No response occurs.
What type of receptors activate guanine nucleotide-binding proteins?
G-protein coupled receptors.
What is the role of enzyme-coupled receptors?
They activate the catalytic activity of intrinsic or associated enzymes.
What is the ultimate response of a cell to multiple signals?
Combination of signals leads to an ultimate response.
What type of signals are typically hydrophilic and bind to cell surface receptors?
- Peptides
- Proteins
- Hormones
What is signal transduction?
The conversion of a signal into a cellular response.
Why do cells need to communicate?
To coordinate their actions and functions in response to environmental changes.
What is the main function of molecular switches in signaling?
To toggle between active and inactive states.
What is the significance of DNA binding domains in receptors?
- specific target genes contain specific DNA sequences in their regulatory gene regions
- DNA binding domains differ in different receptors
What distinguishes local signaling from long-distance signaling?
Local signaling occurs between adjacent cells, while long-distance signaling occurs between distant cells.
Fill in the blank: Signals that can cross the plasma membrane are ______.
hydrophobic small molecules.
What is an example of a signal that is released strictly local?
Acetylcholine in the synaptic cleft.
What is the role of steroid hormone receptors?
They have binding sites for both steroid hormones and DNA sequences.
2 categories of signals
- Signals generated by cell-cell contact
- Signals generated by free diffusion of ligand between adjacent cells (local signalling) or distant cells (long distance signalling)
What is the significance of steroid binding domains in receptors?
- specific hormones bind to specific ligand binding domains
- ligand binding domains differ in different receptors
Examples of signals that can act over a long or short range
- paracrine signalling occurs via a short distance
- neuronal signalling occurs in the synaptic cleft
- endocrine signalling via the bloodstream is remote
- no signal release in contact signalling
3 types of cell surface receptors
- Ion channel coupled receptor
- G protein coupled receptor
- Enzyme coupled receptor
