Week 6- Chemical Mediators/Signal Transduction Flashcards
the receiving cell, which could be another nerve, a muscle, or a gland cell
postsynaptic cell
name two lipid-soluble hormones
steroid and thyroid
Second messenger activation through signal transduction pathways alter protein structure through ______ and ______
Kinase activation (add/take away a phosphate)
Covalent modulation (change function or productivity of a protein)
what does DAG do?
activates protein kinase C (PKC) , which phosphorylates a lot of different proteins in the cell, causing multiple effects
Absorptive Stage
Digestion, carried through the villi in bloodstream, glucose stored in liver, signaling an insulin response, getting glucose into cell
Neurohormones in adrenal medulla are _______
- Made on the spot
- Stored ahead of time
Stored ahead of time in secretory vesicles for rapid use later on
estrogen/testosteron aldosterone cortisol
steroid hormones and are lipid soluble
A neurotransmitter is an example of _______
- autocrine
- paracrine
- endocrine
paracrine
Post-absorptive Stage
Blood sugar drops and starts to release energy from stores, pancreas releases glucagon, sends message to liver to change glycogen into glucose to be made available.
How do endocrine signals (hormones and neurohormones) travel once released by the cell?
Through the blood to their target cell
name two water-soluble hormones
peptide and catecholamine
______ are released by nerve cells but require the blood for transport to a target
neurohormones
How do nerve signals (neurotransmitters) travel once released by the cell?
Across the synapse to the postsynaptic cell
a neurotransmitter that operates in the neuromuscular junction
acetylcholine
_____ add phosphates to proteins, altering their confirmation, thus potentially their function
Kinases
the nerve cell that releases the neurotransmitter
presynaptic cell
Name the 3 important second messenger pathways
- cAMP formed from activation of effector adenylate cyclase 2. IP3 and DAG formed from activation of PKC (phospholipase C). IP3 acts to increase calcium release from the smooth endoplasmic reticulum 3. Calcium, which can enter from outside the cell or from the ER via IP3 activation, can bind calmodulin
The hormone-secreting cell
Effector Cell
The hormone-receiving cell
Target Cell
_____hormones cannot be synthesized in advanced and stored, and they are made “on demand” and are not synthesized until the stimulus for release is received by the endocrine cell
Lipid-soluble hormones
General response to these signals is to alter gene transcription, often find their receptors in cytoplasm or nucleus
lipid-soluble signals
insulin and glucagon, hypothalamic-releasing factors
peptide hormones and are water soluble
A single enzyme molecule can convert multiple substrates into products via the phosphorylation of cellular proteins , this is important because they serve to amplify an initial signal many times over in the cell, producing multiple outcomes from one original signal
Enzyme Cascade
adenylate cyclase uses ATP to make _______
cAMP
Where is norepinephrine released from?
The adrenal medulla
3 examples of neurotransmitters
norepinephrine serotonin dopamine
Stimulation usually results in the increase in _____ and _____ levels in the cell, which activates kinases and convert cholesterol into steroid hormones in the smooth endoplasmic reticulum of the cell
calcium and cAMP
secreted by the same cell, which is the target cell
autocrines
Long-term response to stress (ACTH) is made in the _____
adrenal cortex
_____ have different chemical properties that influence their synthesis, release, transport, and location of the receptor on their target cell
Hormones
insulin released from the pancreas or cortisol released from the adrenal cortex are examples of?
hormones
a cell targets a distant cell through the bloodstream
endocrine
what does IP3 do?
Opens calcium channels by targeting the outer membranes of the endoplasmic reticulum making them leaky to calcium
Secreted by an effector cell into the extracellular space and act on a target cell nearby
paracrines
Short-term response to stress (epinephrine and norepinephrine) is made in the ______
adrenal medulla
are lipid soluble and go directly to nucleus
steroid hormones
name of effector protein
adenylate cyclase
______ is a neurohormone and is released from the adrenal medulla
Norepinephrine
_____ hormones are synthesized in advance, since they are not soluble in lipids, they can be stored in secretory vesicles until release is triggered
Water-soluble hormones
Find receptors on surface of cell and often activate the signal transduction pathways
Water-soluble signals
are water soluble and attach to cell membrane
catecholemines
