Cellular communication Flashcards
external signals are converted to
responses within the cell
the 3 steps of cell communication
signal reception,transduction,response
signal transduction pathway is a specific cellular response in a _____
series of steps
(yeast and animal) and (bacteria and plant) are very similar in what way
share evolution history
what is local signaling
cells are touching,close,direct contact
cell junctions in animal cells
cytoplasm are connected and signals pass freely
cell junction in plant cells
plasmodesmata
cell to cell recognition
process where ANIMAL CELLS may communicate via DIRECT CONTACT between membrane-bound cell-surface molecules
there are gaps in the cell junction (in plant and animal cells) because
things can pass between cells when attached together
what usually passes through cells when they are connected
solute
signals
organisms
organelles
difference between cell junction and cell to cell recognition
cell to cell recognition is still directly touching but with membrane-bound cell surface molecules signals can move one way or both
long distance signaling happens in what types of cells
plants and animals
endocrine signaling is
a type of long distance signaling and only in animals and in the endocrine system
the chemical messenger in the endocrine system
chemical messenger
how does the endocrine signaling work
specialized cells release hormones
hormones travel via the circulatory system (transported wherever the hormones are going)
hormones will then reach target cells,recognize/ and respond to the hormones.
target cells are
The certain cell a signaling molecule has to go to
hormones vary wildely
in size and type (structure determine function)
example of hormones
ethylene
hormones vary wildely
in size and type (structure determine function)
example of hormones
ethylene
insulin
steroids
what are the 3 stages of cell signaling
reception
transduction
response
how does the plasmodesmata pass stuff through their cells
when signaling substances dissolve in the cytosol it can pass freely between cells
another type of cell signaling (secretion)
when cells secrete messenger molecules that regulates close by it would influence cells in the vicinity
growth factor
a local regulator that stimulates nearby target cells to grow and divide
can numerous cells receive and send a response at the same time
yes
paracrine signaling
secretion of signaling molecules to nearby cells (affects the growth factor).the growth factor then takes place
synaptic signaling
an electrical signaling moving along a nerve cell triggers the secretion of neurotransmitter molecules carrying a chemical signal.These molecules diffuse across the synapse triggering a response in the target cell
hormones are chemicals in
both plant and animal cells specifically for long distance signaling
3 major types of receptors
- g-protein coupled receptors (GPCR)
- receptor tyrosine kinase (RTK)
3.Ion channel receptor
G-protein
a protein that binds the energy rich molecule GTP (which is like ATP but instead of Adenosine its Guanosine)
reception steps
1.target cell detects the signaling molecule from outside of cell
2.when cells receptor binds to signalling molecule,the chemical signal is detected
reception can also happen in the
cell near the nucleus
the receptor proteins allow
the cell to detect the signaling and respond to it
the signaling is like a lock and key how
the signaling protein is complementary in shape to a specific site on the receptor and attached there
the signaling is like a lock and key how
the signaling protein is complementary in shape to a specific site on the receptor and attached there
ligand
a molecule that specifically binds to another molecule. a signaling molecule acts like a ligand
ligand binding causes
a receptor protein to change shape.
shape change usually
directly activates the receptor to interact with other cellular molecules
most signaling receptors are
plasma membrane proteins
ligands are ______ and ______ which means
water soluble/large, the ligands are water soluble but its to large for it to move through the plasma membrane
where is the GPCR found and what does it work with
its found on the cell surface transmembrane and works with the help of the G-protein
what is GPCR used for
yeast mating factors
epinephrine
NTs
Hormones
embryonic development ( there sensory receptions)
Receptor Tyrosine Kinase (RTK) contains what that differentiates it from other surface receptors
it has natural enzymatic activity
kinase
enzyme that catalyzes transfer of phosphate groups
where are the receptors of RTK placed
part of the receptor extends into the cytoplasm
the receptor functions as
trrosine kinase
the tyrosine kinase function is
it catalyzed transfer of phosphate group from ATP to tyrosine on a substrate protein
a single RTK can
activate 10+ different transduction pathways
the RTK finally activates once
the signaling molecule attaches
ligand-gated ion channel
is a membrane receptor with a region that can act as a gate for ions when the receptor assumes a certain shape
when a signaling molecule binds as a ligand to the ion channel receptor protein what happens
the gates opens or closes,allowing or blocking the diffusion of specific ions such as Na+ or Ca+,through a channel in the portien
the gate in the ligand area receptor will
change chape
