Cell Signalling Flashcards
what are some types of effector proteins?
transcription factor, cytoskeleton proteins, metabolic enzymes
signals can tell the cell to
survive, grow+divide (mitosis), differentiate, D I E
plasma membrane is impermeable to ______ molecules
hydrophobic
what are the two types of delivery signals?
cell-surface receptors and intracellular receptors
what are intracellular receptors?
carrier proteins brings a small hydrophobic to the cell and goes through the membrane
what are cell-surface receptors?
signal molecule arrives at a receptor protein that will relay signal to the inside
what are the 5 forms of intracellular signaling based on distance?
contact-dependent, paracrine, synaptic, autocrine, endocrine
what is contact-dependent signaling?
signaling and target cell needs physical contact
what is paracrine signaling?
cell secretes signal and cells around them receive the signal with receptors
what is synaptic signaling?
cell body that can stretch and neutrotransmitter is released in synapse
what is autocrine signaling?
cell secretes a signal and binds to its own receptor
what is endocrine signaling?
cell secreting the stimulus is far so endocrine organs that secrete hormones through bloodstream
what are the 2 types of response once a signal is received?
fast- protein is ready and stimulus will alter protein (change conformation or have it interact with another protein)
slow- needs to make protein from scratch. signal will activate transcription
the same stimuli interacting with the different cells will
have a different response
what does acetylcholine do in the heart pacemaker cell?
decreased rate of firing
what does acetylcholine do in the salivary gland cell?
salivary secretion
what does acetylcholine do in the skeletal muscle cell?
contraction
what are the 3 major classes of transmembrane receptor?
- ion-channel linked
- g protein linked
- enzyme-linked (receptor is an enzyme itself or associated with an enzyme)
what is an ion-channel-coupled receptor?
signals change the behavior of ion channel usually opens up and lets ions inside
what is a g-protein coupled receptor?
g protein activates when signal binds to receptor (spans 7 times on membrane). g protein will act on further enzymes.
what is an intrinsic enzyme activity?
receptor itself is an enzyme
what is an associated enzyme activity?
receptor is closely associated with an enzyme
how does the receptor relay info to the inside?
- conformational change of receptor
2. multimerization of receptor
what are second messengers?
small diffusable molecules produced by signaling enzymes that affect target proteins
describe signaling by phosphorylation
protein kinase that does phosphorlyation
protein phosphatase reverses kinase effect
what is phosphorylation?
phosphate group taken from ATP to be put on amino acid. not necessarily activating, just changes conformation
what does phosphorylation?
altered conformation, target for protein breakdown, new protein-protein binding site
what is the monomeric g protein?
one, small g-protein
what is heterotriemeric g protien?
3 part, one part binds to g protein
what is subcellular localization?
signaling is more efficient is the necessary parties are found near each other
what is a scaffold protein?
hold enzymes that will interact with receptor
what is an activated receptor?
receptor has binding sites for necessary enzymes on cytoplasmic domain
what is phopsoinositide docking sites?
???? tiddy?
what are modular binding domains?
a protein most likely to have several modular segments
what are adaptor proteins?
proteins that are composed solely of protein-protein interaction domains. act as a link.
what are effector proteins?
protein that plays a central role in the change in cell response
what is positive feedback?
A activates B and B further activates A
what is negative feedback?
A activates B and B inhibits A