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Biophysics MCQs PMU 1st YR/2nd Sem

Beschreibung

Biophysics mcqs
Med Student
Quiz von Med Student , aktualisiert more than 1 year ago
Med Student
Erstellt von Med Student vor mehr als 8 Jahre
1011
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Zusammenfassung der Ressource

Frage 1

Frage
Action potential of neurons is mainly a result of
Antworten
  • Na and K
  • Na and Mg
  • Ca and K

Frage 2

Frage
Strength of ion currents during action potential is related to
Antworten
  • Duration of hyperpolarisation action potential phase
  • Equilibrium potentials of ions
  • Distance from point of stimulation

Frage 3

Frage
During action potential which quantity is altered
Antworten
  • Permeability of membrane for diffusion types of ions
  • Diametric permeability of membrane
  • None

Frage 4

Frage
Membrane potential operated channels are on
Antworten
  • active fixed value
  • permanently active
  • active in certain range in membrane potential

Frage 5

Frage
Mark correct
Antworten
  • all the ion channels
  • all the ion channels let pass
  • ion flow depends on ion type and membrane potential

Frage 6

Frage
Ion channel blockers
Antworten
  • Universal
  • Specific to given channels
  • Chemical substances attached to the channel during action potential

Frage 7

Frage
Ion channels are filled with
Antworten
  • water
  • air
  • lipid

Frage 8

Frage
Action potential is
Antworten
  • alteration of electric polarity of the membrane when cell moves
  • membrane response to over-threshold irritation
  • nonelectric quantity with chemical nature

Frage 9

Frage
At physiological condition cell membrane is
Antworten
  • solid structure
  • gas
  • liquid-crystal structure

Frage 10

Frage
Membrane hyperpolarization leads to
Antworten
  • elevation of the membrane potential
  • decrease of the membranes potential
  • alteration of membrane charge sign

Frage 11

Frage
Membrane depolarization leads to
Antworten
  • Elevation of membrane potential
  • Decrease of membrane potential
  • Noe

Frage 12

Frage
Resting potential of cell membrane is measured in
Antworten
  • Megavolts
  • Volts (v)
  • Millavolts (mv)

Frage 13

Frage
Action potential duration ten times of
Antworten
  • seconds
  • milliseconds
  • nanoseconds

Frage 14

Frage
Which term is not related to action potential
Antworten
  • Overshoot
  • Entropy
  • Depolarisation
  • Threshold

Frage 15

Frage
During the action potential
Antworten
  • cation currents from intercellular to extracellular
  • cation currents from extracellular to intercellular
  • none of above

Frage 16

Frage
The first law or principle of thermodynamics(TD) is defined for
Antworten
  • covered TD system
  • closed TD system
  • opened TD system

Frage 17

Frage
The ionophores are
Antworten
  • ions used in medicine
  • transport molecules
  • ions after the ion polarisation

Frage 18

Frage
Blocking of Na/K pump working non-electrogenous in stage
Antworten
  • make depolarization of cell membrane
  • make hyperpolarisation of cell membrane
  • make no alteration of cell membrane

Frage 19

Frage
The administration of the blocker tetradotoxin led to alteration of following stage of action potential
Antworten
  • repolarisation phase
  • shape and type of trace potentials
  • depolarisation phase

Frage 20

Frage
Electrochemical potential is measured by
Antworten
  • direct method with non polarized electrodes
  • by the disperse phase velocity in constant electric field
  • direct method- electrophoresis with constant electric field

Frage 21

Frage
In Boltzmann equation
Antworten
  • entropy is directly proportional to the temperature
  • entropy logarithmically depends on the thermodynamic probability
  • entropy is directly proportional to the thermodynamical probability

Frage 22

Frage
The filaments of muscles are based on
Antworten
  • actin fibers
  • troponin globules
  • myosin fibers

Frage 23

Frage
In cell membranes are present
Antworten
  • hydrophobic interactions omly
  • hydrophilic interactions only
  • both types

Frage 24

Frage
The basic condition for arising of membrane potential
Antworten
  • difference of ion concentration on the two sides of them
  • difference of temperature concentration on two sides of the membranes
  • "one way" permeability of the membrane

Frage 25

Frage
The classic electrophoresis is performed by
Antworten
  • a constant current
  • alternated current
  • magnetic field

Frage 26

Frage
Smooth muscles are two types
Antworten
  • phasic and tonic
  • tonic and synergic
  • phasic and antagonistic

Frage 27

Frage
In smooth muscle
Antworten
  • Only phosphorylated myosin can bind to actin
  • Ca2+ calmodulin causes phosphorylation of myosin light chain kinase(MLCK)
  • Phosphorylated MLCK causes phosphorylation of myosin
  • A, B and C
  • None of the above

Frage 28

Frage
Each globular head group (often called a crossbridge) of a myosin molecule of skeletal muscle contains:
Antworten
  • A binding site for the attachment of troponin
  • A binding site for the attachment of tropomyosin
  • An actin binding site and a myosin ATPase site
  • One site which binds troponin and another which binds tropomyosin
  • A site which is phosphorylated by protein kinase A(PKA), thereby allowing interaction with actin

Frage 29

Frage
In order to make ATP (adenosine triphophate) in muscles, creatine phosphate (CP) transfers ________________ to adenosine diphosphate (ADP)
Antworten
  • Oxygen
  • Phosphate
  • Adenosine

Frage 30

Frage
A sacromere is part of a
Antworten
  • Myofibril
  • Myofilament
  • Endomysium
  • Perimysium

Frage 31

Frage
Differences between striated (skeletal, cardiac) muscle and unstriated (smooth) muscle include:
Antworten
  • only unstriated muscle is innervated by autonomic nervous system
  • only striated muscle exhibits pacemaker activity
  • striated muscle can contract in the absence of extracellular Ca2+, but unstriated muscle cannot
  • only unstratied muscle has gap junctions
  • none of the above are true

Frage 32

Frage
As a skeletal muscle contracts
Antworten
  • The A bands become shorter
  • The I band become shorter
  • Adjacent Z lines become farther apart
  • The H zones don't change in size
  • The M lines become shorter

Frage 33

Frage
The period of contraction of a typical ventricular muscle fiber is
Antworten
  • about the same as that of a typical slow skeletal muscle fiber
  • shorter than that of a typical atrial muscle fiber
  • slightly longer in duration than the action potential in the ventricular fiber
  • slightly shorter in duration than the action potential in the ventricular fiber
  • longer in duration than contraction in any smooth muscle cell

Frage 34

Frage
The transverse tubular system of skeletal muscle
Antworten
  • has a very small lumenal volume and large surface area relative to the cytoplasmic volume and surface area of the fiber
  • propogates action potentials at about the same speed as the surface membrane
  • forms gap junctions with the sacroplasmic reticulum (SR)
  • never comes closer than about 1 micron from the SR membrane
  • does not contain voltage-gated Na+ channels

Frage 35

Frage
During the plateau (phase 2) of the ventricular action potential
Antworten
  • Na+ channels remain open causing the continued depolarization
  • Ca2+ channels are mostly closed
  • K+ permeability of the membrane is greater than when the membrane is at rest
  • Both Ca2+ and K+ permeability of the membrane is lower than when the membrane is at rest
  • none of these

Frage 36

Frage
Contractility (or inotropic state) of cardiac muscle is increased by
Antworten
  • increased stretch of cardiac muscle (e.g increased filling of the heart)
  • increased myoplasmic Ca2+ during systole
  • Ca2+ channel blockers
  • Decreased coronary blood supply
  • Both A and B will increase contractility

Frage 37

Frage
The sequence for smooth muscle contraction is....
Antworten
  • increased cytosolic calcium, which binds to troponin, complex binds with myosin light-chain kinase which uses ATP to phosphorylate myosin cross-bridges, which bind to actin filaments, resulting in contraction
  • increased cytosolic calcium, which binds to calmodulin in cytosol, which binds with myosin cross-bridges resulting in contraction
  • increased cytosolic calcium, which binds to calmodulin in cytosol, which moves tromyosin from blocking active sites on actin filament, which binds with myosin cross-bridges, resulting in contraction
  • increase cytosolic calcium, which binds to troponin, which moves tropomyosin from blocking active actin filament, which binds with myosin cross-bridges resulting to contraction

Frage 38

Frage
The neuron action potential starts with
Antworten
  • Na+ influx
  • Na+ eflux
  • N+ influx

Frage 39

Frage
The membrane potential after accessing its maximal valve by constant condition
Antworten
  • Remain stable in time
  • Decrease exponentially
  • Slowly close resting membrane potential

Frage 40

Frage
The trans-membrane proteins in difference with peripheral
Antworten
  • do transversal diffusion
  • have hydrophilic and hydrophobic parts
  • possess mainly enzymes activity

Frage 41

Frage
The most punctual definition of membrane potential valve is defined with the equation of
Antworten
  • Goldman
  • Nernst
  • Bernstein

Frage 42

Frage
Sodium-potassium pump in electrogenic condition
Antworten
  • depolarized cell membrane
  • repolarized cell membrane
  • hyperpolarized cell membrane

Frage 43

Frage
TTX tetrodoxin is a blocker of
Antworten
  • potassium channels
  • sodium channels
  • calcium channels

Frage 44

Frage
The contraction of striated muscle
Antworten
  • faster than smooth muscle
  • slower than smooth muscle
  • equal to smooth muscle

Frage 45

Frage
Thin filaments of muscle
Antworten
  • Actin fibers
  • Troponin
  • Myosin fibers

Frage 46

Frage
Striated muscles are characterized
Antworten
  • perodically alter
  • equal to zero membrane potential
  • stable resting

Frage 47

Frage
Source of calcium needed for contraction striated muscle (rapid transition)
Antworten
  • Extracellular
  • Endoplasmic Reticulum
  • Motor Neurons

Frage 48

Frage
Hyperpolarisation phase of striated muscles
Antworten
  • Preliminary to the stiulus
  • Repeats twice after each action potential occurs
  • Is missing

Frage 49

Frage
Mark the correct expression
Antworten
  • all ion channels let pass ions from extra to intra cellular compartment
  • all ion channels let pass ions from intra to intra cellular compartment
  • ion flow depends on ion type and membrane potential

Frage 50

Frage
The membrane theory of excitation is based on the idea that stimulation of the surface membrane of an excitable cell causes a molecular restructuring that alters the membrane’s permeability and gives rise to transmembranous ion currents
Antworten
  • True
  • False

Frage 51

Frage
Source of calcium needed for contraction striated muscle tissue (rapid transition) is
Antworten
  • Extracellular
  • Endoplasmic Reticulum
  • Motor Neurons

Frage 52

Frage
Contraction of smooth muscle is _____________ than that of skeletal muscle
Antworten
  • slower
  • faster
  • equal

Frage 53

Frage
The trans-membrane transport (transdiffusion) is similar to
Antworten
  • A filtration
  • A passive membrane transport
  • An active membrane transport

Frage 54

Frage
Smooth muscle's slow wave is defined by
Antworten
  • Concentration of Na+, K+ and Ca2+
  • Concentrations of Na+, K+ and Ca2+ pump
  • Concentrations of Na+, K+ and Na/K pump

Frage 55

Frage
Order the polarizations according to their time of appearing
Antworten
  • Ionic, Dipolar, Macrostructural
  • Surface, Dipolar, Ionic
  • Surface, Macrostructural, Dipolar

Frage 56

Frage
The membrane potential after reaching maximum value
Antworten
  • Remains constant in time
  • Is altered slowly to submaximal value
  • Decreases to zero

Frage 57

Frage
The membrane lipids are
Antworten
  • amphiphilic
  • formed glycocalcs
  • have many transport function

Frage 58

Frage
The lipids are
Antworten
  • transmembrane
  • membrane receptor
  • organized in layers

Frage 59

Frage
The plateau phase of myocardial cells is determined by
Antworten
  • Concentrations of Ca2+ and Na+
  • Concentrations of Ca2+ and K+
  • Concentrations of Na

Frage 60

Frage
Membrane potential depends on
Antworten
  • temparature of the thermodynamic system
  • viscosity of the medium
  • medium's protein/lipid ration
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