The known inter-cellular information systems are:
a) chemical and electrical;
b) mechanical, chemical, and electrical;
c) biochemical.
Of the following inter-cellular communication systems, which one is distributed throughout the entire organism?
a) the chemical;
b) the mechanical;
c) the electrical.
. The information carriers of the chemical inter-cellular communication are:
a) receptors;
b) signaling molecules;
c) synaptic cleft.
Endocrine system communication belongs to the class of:
;
a) mechanical inter-cellular communication;
b) chemical inter-cellular communication
c) electrical inter-cellular communication.
Which of the following functions is not characteristic for receptors?
a) secretion of signaling molecules;
b) activation of second messenger systems;
c) transmembrane signal transduction.
Membrane receptors are:
a) information signaling molecules;
b) vesicles filled with neurotransmitters;
c) element of the chemical information system of the body.
Are signaling molecules specific to given receptors?
a) not specific;
b) specific, but not uniquely specific;
c) they are uniquely specific.
Is it possible for a given receptor to interact with multiple different signaling molecules?
a) no, because a given receptor interacts only with one type of ligand;
b) yes, because any given receptor can interact with all ligands;
c) yes, a given receptor can interact with several signaling molecules, with similar structure.
Is it possible for a given type of signaling molecule to interact with multiple types of receptors?
a) not possible;
b) a given signaling molecule can activate all membrane receptors;
c) its common for a ligand to interact with several types of receptors.
What are the functions of second messengers?
a) they carry the information from receptors to cellular effectors or to cyclic cascades that amplify the signal;
b) they interact with first messengers (signaling molecules) in the extracellular fluid, and carry the information to receptors;
c) they interact with membrane receptors from the intracellular side and cause secondary activation of receptor proteins.
To decrease the inflow of extracellular information, cells use the following mechanism:
a) migration toward locations with smaller information inflow;
b) passing the information overflow to neighbouring cells;
c) decreasing the number of membrane receptors, responsible for the specific information.
Which of the following structures is an integral part of the chemical information system?
a) membrane receptors;
b) DNA molecules;
c) actin molecules.
Desensitisation of a receptor is the condition where:
a) the cell does not synthesise a sufficient number of given type of receptors;
b) activated receptors generate less than the usual number of second messengers;
c) there is a structural degradation of membrane receptors.
The principle of recognition between ligands and receptors is called:
a) complementarity;
b) bifocal;
c) positive-negative match;
The neurotransmitter acetylcholine activates:
a) nicotinic and muscarinic receptors;
b) nicotinic receptors;
c) muscarinic receptors.
Atropin is:
a) muscarinic agonist;
b) muscarinic antagonist;
c) nicotinic agonist.
Nicotinic acetylcholine receptors (nAChR) function as:
a) ligand-gated Ca2+ ion pumps;
b) voltage-gated Na+ channels;
c) ligand-gated Na+ channels.
Cyclic adenosine monophosphate (cAMP) function as:
a) G-protein;
b) second messenger (intracellular);
c) first messenger (inter-cellular).
The second messenger molecule that opens calcium channels on the membrane of the endoplasmic reticulum is:
a) inositol triphosphate (IP3);
b) diacylglycerol (DAG);
c) cyclic adenosine monophosphate (cAMP).
What is the function of the membrane receptors?
a) transduce information from extra- into intra-cellular space;
b) transfer protein molecules from extra- into intra-cellular space;
c) induce phase transitions in membrane lipid molecules.
Receptors are characterised with:
a) high-affinity, high-specificity, and reversible bonding to signaling molecules;
b) high-affinity, low-specificity, and reversible bonding to signaling molecules;
c) high-affinity, high-specificity, and irreversible bonding to signaling molecules.
Which of the following is a necessary condition for direct electrical communication between cells?
a) cells must be of the same type;
b) cells must be submerged in electrolyte solution;
c) cellular membranes must be connected.
Connexons (gap junctions) allow for:
a) electrical communication between cells;
b) chemical and electrical communication between cells;
c) chemical communications between cells.
Which of the following terms dos not refer to a type of inter-cellular communication?
a) paracrine;
b) autocrine;
c) endogenic.
Receptors are not:
a) membrane structures;
b) cytosol proteins;
c) extracellular structures.
Membrane receptors connected to G – proteins, are large proteins that cross the membrane lipid bilayer:
a) 7 times;
b) once;
c) different number times, depending on the receptor.
Upon activation by a ligand, receptor tyrosine kinase (RTK) will:
a) activate Ca2+ ion channels;
b) auto-phosphorylate and trigger cytosolic signaling cascade;
c) depolarise the membrane and cause action potential.
. Receptors of the cellular membrane are:
a) lipids or glycolipids;
b) proteins or glycoproteins;
c) polymeric carbohydrate.
Which of the following receptors do not get activated by acetylcholine?
a) muscarinic receptors;
c) tyrosine receptors.
Which of the following types of complementarity is not present between membrane receptors and ligand molecules?
a) spatial;
b) magnetic;
c) electric.
Can action potentials be used for inter-cellular signaling?
a) no, action potentials do not travel through the extracellular medium;
b) yes, all cells use action potentials for communications;
c) yes, some cell types use it (neurons, visceral smooth muscles, cardiac muscles).
When acetylcholine bonds to a muscarinic cholinergic receptor of the membrane of smooth muscles, the following ions are released into the cells:
a) sodium ions;
b) calcium ions;
c) potassium ions.
According to their interaction with the membrane, receptors are:
a) transmembrane (integral) proteins;
b) surface membrane (integral) proteins;
c) proteins diffusing through the membrane.
When acetylcholine bonds to a nicotinic cholinergic receptor, the following membrane channel is opened:
a) Na+ ion channel;
b) G-protein coupled channel;
c) Ca2+ ion channel.
Signaling molecules that bond to receptors are called:
a) first messenger or ligand;
b) second messenger;
c) cellular effector.
Which of the following functions is characteristic for the receptors:
a) they recognise the complimentary ligands but allow docking only when the cell needs the carried information;
b) upon recognition, they allow docking of the type of signaling molecules that are required by the current needs of the cell;
c) they interact with complimentary ligands on probabilistic principles (the higher the concentration the higher the chance of interaction).
What is the first process that follows the docking of a ligand to a receptor?
a) change of the conformation state of the ligand;
b) change of the conformational state of the receptor;
c) the receptor updating its status on facebook.
