1.4: Communcication and Signalling. Flashcards
Type of signalling molecule sent between cells in a multicellular organism.
Extracellular
Examples of extracellular signals.
Steroid hormones OR Peptide hormones OR Neurotransmitters.
Target cell protein with a binding site for a specific signal molecule.
Receptor.
Consequence of the change of conformation of receptor resulting from binding with a signalling molecule.
Response initiated.
Term for different cell types responding differently to the same signal.
Tissue-specific
Type of signalling molecule that can diffuse through the phospholipid bilayer of a membrane.
Hydrophobic signalling molecules.
Examples of hydrophobic extracellular signalling molecules.
Steroid hormones OR Oestrogen Or Testosterone.
Role of receptors for hydrophobic signalling.
Transcription factors.
Site of receptors for steroid hormones.
Cytosol or Nucleus
DNA sequence to which a steroid hormone-receptor binds to affect the expression of many different genes.
Hormone response element OR HREs
Affect of transcription factor protein bound to the DNA HREs on the rate of transcription.
Stimulate OR Inhibit
Type of molecules that cannot pass through a membrane phospholipid bilayer.
Hydrophilic
Examples of hydrophilic extracellular signalling molecules
Peptide hormones Or Neurotransmitter
Protein which responds to the binding of a hydrophilic extracellular signalling molecule by undergoing a conformational change.
Surface Receptor OR Transmembrane Receptor
Consequence of the surface receptor undergoing a conformation change in response to the binding of a peptide hormone.
Transduction (across the plasma membrane).
Act as signal transducers by converting extracellular ligand-binding into an intracellular signal.
Transmembrane receptor.
Protein attached to an activated receptor that relays the signal to a target protein kinase enzyme to begin a protein kinase cascade.
G-protein.
Term of one protein kinase phosphorylating many others. Then phosphorylate many more.
Cascade
Peptide hormone involved in the regulation of blood glucose.
Insulin
Type of glucose transporter protein recruited to the cell membrane as a result of insulin binding to it’s receptor.
GLUT4
Type of enzyme cascade that leads to GLUT4 vesicles being transported to the cell membrane.
Phosphorylation OR Protein kinase
Types of cell in which GLUT4 is most active in glucose regulation.
Fat AND Muscle.
Type of diabetes mellitus caused by failure to produce insulin.
Type 1
Type of diabetes mellitus caused by loss of insulin receptor function
Type 2
Which type of diabetes is associated with obesity.
Type 2
Reason exercise improves the health of people with type 2 diabetes.
More GLUT4 receptors recruited OR Weight loss.
Inside of a neuron is negative compared to the outside and no net flow of ions across the membrane.
Resting potential.
Wave of depolarisation of the membrane that travel along the entire length of a neuron.
Action potential.
Initiate a response by binding to ligand-gated ion channel receptors at a synapse.
Neurotransmitters
Ions that move into a neuron when ligand-gated ion channel open.
Na+
Channels that open to allow Na+ to flow down the electrochemical gradient once depolarisation passes the threshold value.
Voltage-gated sodium
Ion that moves out of the neuron once the sodium channels are inactivated.
K+
Released into the synapse once the action potential reaches the end of the neuron.
Neurotransmitters.
Pump that re-establishes the ion concentration gradients of a resting potential.
Na+/K=-ATPase.
Retinal photoreceptor cells that need bright light and are responsible for colour vision.
Cones.
Retinal photoreceptor cells that can function in dim light but do not allow colour perception.
Rods.
The light sensitive molecule that combines with the membrane protein opsin to form photoreceptors.
Retinal
Name for the retinal-opsin complex in rod cells.
Rhodopsin
Change in rhodopsin conformation when retinal light absorbs a photon of light.
Photoexcited
Name for the hundreds of G-protein molecules activated by a single photoexcited rhodopsin.
Transducin
Enzyme activated by each transducin G-protein and name for the thousands of molecules hydrolysed by it.
PDE and Cyclic GMP/ cGMP.
Affect of low rod cell cGMP levels.
Ion channels closed AND Triggers nerve impulse.
Term for one photpexcited molecule starting a series of reactions involving a greater number of molecules at each step.
Cascade.
Term for cascade if proteins allowing rod cells being able to respond to low intensities of light.
Amplification.
Combine to produce different photoreeptor proteins in cone cells.
Retinal AND Different Opsin proteins.
Wavelengths of light detected by cone cells.
Red AND Blue AND Green AND UV.
