Exam 3 lecture 17 Flashcards
what happens after a ligand binds to a receptor in intracellular signaling?
take on a new shape, may make it active as an enzyme or let it bind to another molecule.
Define Signal transduction.
The signal is transmitted through the membrane and into the cytoplasm via interactions among several molecules.
How is signal transduction initiated?
how does it occur?
By a ligand binding to a receptor.
and it only occurs with cell-surface receptors.
Methods of signal transduction
1.) phosphorylation
2.)second messengers
define phosphorylation
addition of a phosphate group (pO4) to a protein or a nucleotide.
define steps second messenger
small molecules that propagate a signal after it has been initiated by the binding of a ligand to the receptor.
bind and alter the behavior of proteins in a cell
- including ca2+, c AMP and cGMP
In phosphorylation define Kinase
an enzyme that catalyzes the addition of a phosphate group to a protein or a nucleotide.
what are the steps for cellular response to signal transduction
( 4 steps)
1.)changes to a gene expression; either transcription or translation
2.) increase in cellular metabolism
3.) activate mitosis ( cell division)
4.)activate apoptosis (cell death)
MAP kinase pathway is an example of what singalins
paracrine cell signaling
steps for map kinase pathway- or what it is
that helps cells respond to signals like growth factors.
involves a chain of proteins (MAPKKK → MAPKK → MAPK) that activate each other. This leads to changes in gene expression, cell growth, or survival.
What is FGGY
carbohydrate kinase domain
FGGY increases what
in expression in myofibers during muscle atrophy.
FGGY comes in how many isoforms
2
Hypothesis for study is FGGY does what
attenuates the map kinase pathway by inhibiting ERK phosphorylation.
in the study how did they test the hypothesis
Artificially increasing the expression of a specific gene by introducing additional copies of a genes on expression vectors
what are the ligand and receptors in AKT signaling
L= growth factor
R= RTK
Describe AKT signaling pathways
controls cell survival, growth, and metabolism. It starts with a signal (like insulin) activating PI3K, which produces PIP3. AKT binds PIP3, gets activated, and triggers processes like cell survival and protein synthesis.
How does FGGY contribute to atrophy?
energy imbalance, glucose metabolism disruptions, increased proteolysis chronic conditions.
2 main types of synapse what are they?
1.) chemical
2.) electrical
what are the 4 steps of chemical syanpse?
1.) Action potential reaches axon terminal
2.) calcium channel open. nuerotransmitter is released
3.) neurotransmiter binds to receptor on the posysynaptic neuron. gets a response
4.) neurotransmitter removed by reuptake, enzymatic breakdown and diffusion
define chemical syanpse
uses neurotransmitters to transmit signals across a synaptic cleft
define electrical syanpse?
uses gap junction to allow direct ion flow between neurons for fast signaling.
what is the function of synapse
neural communications, reflexes and brain function that include learning and memory.
define synapse
a junction between 2 neurons where signals are transmitted.
