問題一覧
1
Resting potential exists in
Almost all cells and tissues
2
Electrokinetic phenomena are
Phenomena occurring in dispersion systems due to the electric double layer at the interphase boundary between the dispersed phase and the dispersion medium, Electrophoresis, electroosmosis, streaming potential and sedimentation potential
3
In facilitated diffusion the solute
Is transferred through the membrane by a dedicated integral protein under the action of its concentration gradient
4
The theory of indirect effect of radiation on bio-objects is based on
Radiolysis of water and action of its products on biomolecules
5
The known types of dielectric permittivity dispersions in bio-objects ( α-,β-, γ-) are explained by
The sequential disappearance of the electronic, molecular, and orientational polarization of bio-objects when the frequency of the current increases., Elimination of certain type of polarization of the object when the frequency of the current exceeds a relevant critical value
6
Depending on the number of particles transported during one work cycle of the transporter protein, the transport through membranes can be classified as
Uniport and cotransport
7
With the increase of temperature, the transition from gel to liquid crystalline phase state in lipid bilayers is due to
An increase of the number of trans conformations in lipid tails
8
The Target theory for the mechanism of the radiation effect on bio-objects is based on
The existence of structures with increased radio-sensibility, their damage has a fatal effect
9
The ion of which element is most important in muscle contraction?
Calcium
10
The double electric layer around the cells plays a role in: (select one or more)
Electrokinetic processes, The stabilization of cell suspensions
11
Zeta-potential is the value of the electric potential
In the slipping plane
12
Cybernetic systems with negative feedback programs are
Keeping their parameters constant at values given by the program
13
Which of the following membrane conditions activate the voltage-gated (potential-dependent) ion channels?
Depolarization of the plasma membrane
14
Action potential occurs in
Excitable cells and tissues
15
Depending on the energy used, the transport through membranes can be classified as:
Active transport and passive transport
16
The thermodynamic probability a given state of a thermodynamic system is determined by:
The number of microstates defining the macrostate of the system
17
During electromechanical coupling in muscle cells
Depolarization of the sarcolemma precedes muscle contraction
18
The quantity of Information in a message is higher if
The message reports about occurrence of an improbable event
19
The value of the resting potential is most close to
The equilibrium potential of K+
20
During contraction muscle cells convert:
The chemical energy of ATP into mechanical work
21
The following types of movements are common to membrane lipids and proteins: (select one or more)
Lateral diffusion , Rotation around the vertical axis , Trasbilayer motion
22
Depending on the type of their "heads", in physiological conditions the phospholipids are
Polar and negatively charged
23
The free energy F of a thermodynamic system is at its minimum:
At thermodynamic equilibrium
24
Thermodynamic system that exchanges only energy with its surroundings is called:
Closed
25
The singlet oxygen ¹O₂, has two electrons located:
On two separate orbitals having opposite spins
26
Equilibrium membrane potential occurs under the following conditions:
Through the membrane there is a gradient of anions and cations
27
Electric properties of the cell membranes - high resistance and capacitance are due to:
The lipid bilayer of the membrane
28
Which kind transport process is the reason for the generation of membrane potential (Em)
Diffusion of ions
29
During active transport the energy produced by the hydrolyzation of ATP to ADP and P is consumed for:
Conformational change of the molecule of the transporter protein
30
Depending on the type of transported substance, the active transport is divided into:
Transport of K+ / Na+, transport Ca²+ , transport H+ and transport of anions.
31
The lipid molecules in the lipid bilayer interact by:
Non-covalent interactions
32
The lipid bilayer is constructed as
The lipids are arranged in a double layer with the tails from both layers “inside” (facing toward each other)
33
The reactive forms of oxygen include:
¹O₂, O₂‾˙, OH˙ and H₂O₂
34
The depolarization of the membrane of excitable cells in caused by
Passive transport of sodium ions
35
The impedance dispersion of bio-objects reflects
Vanishing of some polarization types with increasing frequency of the current
36
Liposomes are:
Spherical artificial membranes
37
The reactive oxygen species are:
Harmful, because they oxidize and change biomacromolecules
38
At same difference of ion concentration across a membrane, the value of which potential is higher:
The Membrane equilibrium potential (Em) is greater than the Diffusion potential (Ed)
39
Diffusion is:
The movement of the solute molecules from a region with higher to a region with lower concentration
40
K+ / Na+ - pump is present:
In the plasmalemma of almost all cell types
41
As the concentration of ions in the medium increases, the thickness of the diffusion layer of the double electric layer:
Decreases
42
Muscle contraction is due to:
Sliding of the actin and myosin filaments relative to each other due to a conformational change of the head of myosin, for which the energy of ATP is used.
43
Electric properties of the cell membranes - high resistance and capacitance are due to:
the lipid bilayer of the membrane
44
During electromechanical coupling in muscle cells:
depolarization of the sarcolemma precedes muscle contraction
45
The formation of free radicals can be achieved by:
Homolysis, photolysis and radiolysis, single-electron transfer reaction with a suitable endogenous agent
46
The active resistance of the cell membranes is:
Much higher than that the resistance of the cytoplasm
47
Electric double layer around the cells occurs due to:
the presence of dissolved ions , the presence of surface charge of the cell
48
The surface electric charge is generated by:
dissociation of ionogenic surface groups, the adsorption of ions from the solution.
49
The repolarization of the membrane of excitable cells in caused by
Passive transport of potassium ions
50
The sodium and potassium channels in the membrane of excitable tissues
Open and close with the energy of ATP
51
The nerve impulse propagates with the highest speed in:
Myelinated nerve fibers
52
The thin filaments in the sarcomere are made up mostly from:
Actin
53
The thick filaments in the sarcomere are made up from:
Myosin
54
Which of the following membrane conditions activate the voltage-gated (potential-dependent) ion channels?
depolarization of the plasma membrane;
55
Resting potential is
The electric potential on the inner side minus the electric potential on the outer side of the cellular membrane at rest
56
The most susceptible to peroxidation are:
unsaturated fatty acids
57
The osmotic pressure does not depend on:
The molecular mass of the dissolved species
58
What is the tonicity of 0,1 M glucose solution as compared to a solution of 0.1 M NaCl?
Hypotonic
59
What is Osmosis?
It is a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one.
60
What is hematocrit?
It is the ratio of the volume of red blood cells to the total volume of blood.
61
A cell is placed in a solution with different osmotic pressure and begins to inflate. Where the osmotic pressure is higher?
Inside the cell
62
An animal cell is placed in hypotonic solution. How does it change its volume?
The volume of the cell increases
63
What is the tonicity of 0,1 M CaCl2 solution as compared to a solution of 0.1 M NaCl?
Hypertonic
64
What is the osmotic concentration of solution of 0.1 mol/L MgCl2
0.3 Osm/L
65
An animal cell is placed in an isotonic solution. How does it change its volume?
The volume of the cell doesn’t change
66
An animal cell is placed in a hypertonic solution. How does it change its volume?
The volume of the cell decreases
67
During diffusion, the solutes flow amount depends on:
The difference in concentrations
68
Filtration is:
Water transfer through the membrane under the action of hydrostatic pressure gradient
69
Osmosis is:
transfer of water molecules through a semipermeable membrane from a region with a lower to a region with higher osmotic pressure
70
Two solutions are separated by a membrane permeable to Na+ and K+. What determines the diffusion of Na+?
The concentration gradient of Na+
71
A patient is undergoing hemodialysis. The time to reduce the urea concentration in the blood to 50% of its initial value is 60 minutes. How long it is generally necessary to reduce the urea concentration to 25% of the initial value?
120 min
72
During haemodialysis, the flow of a solute species through the dialysis membrane does not depends on:
The dissociation of the solute particles in the solution
73
In a healthy person, the total flow of water out of the capillary into the interstitial fluid (IF) of the surrounding tissue, that is caused by filtration is:
is greater than the total back-flow of water into the capillary from the IF, that is caused by osmosis.
74
During haemodialysis, what substances cannot pass through the pores of the artificial kidney dialysis membrane?
Blood cells
75
The flow of water through the capillary walls in the circulatory system is directed:
out of the capillary into the tissues at the arteriole end of the capillary, and from the tissues into the capillary at the venule end of the capillary
76
How the cell is changing its volume .... (A, B, and C), if the surrounding solution is .... (D, E and F) A. decreases its volume B. increases its volume C. does not change its volume D. isotonic E. hypertonic F. hypotonic
A-E, B-F, C-D
77
Which cation has the highest concentration in the extracellular fluid
Na+
78
78) Resting bio membrane potential is:
the difference between the electrical potentials on the inside and the outside of the cell membrane at rest
79
Diffusion potential occurs under the following conditions:
there is a gradient of anions and cations, the membrane is permeable equally for anions and cations, but their mobility in the medium is different
80
With the same difference in ionic concentration on both sides of the membrane, which potential is greater:
they are the same
81
The value of the resting membrane potential is most close to:
the equilibrium potential of K+
82
Membrane potential is:
the difference in the electric potentials on both sides of the membrane
83
What are the main factors that lead to the emergence of membrane potential?
selective membrane permeability and ion concentration gradient
84
The value of the equilibrium membrane potential for an ion (Em) is a function of:
the ratio of the ion concentrations on either side of the membrane
85
At rest the membrane is most permeable for which of the ions?
K+
86
Partial hemolysis is
the percentage of erythrocytes hemolyzed for certain small interval of time
87
Which erythrocytes are more resistant to acid hemolysis:
the younger erythrocytes