Biophysics MCQs Part 2 PMU- 1st YR/2nd Sem

Description

Biophysics mcqs from pics
Med Student
Quiz by Med Student , updated more than 1 year ago
Med Student
Created by Med Student over 8 years ago
340
7

Resource summary

Question 1

Question
Membrane potential operated channels are
Answer
  • active at fixed value of the membrane potential only
  • permanently active
  • active in certain range of membrane potential

Question 2

Question
Striated muscle are structure bases of
Answer
  • upper levels of gastro intestial
  • lower levels of gastro intestial
  • none of these

Question 3

Question
Muscle extraction is possible when
Answer
  • Ca ions are bounded
  • Ca contraction increase to 10^-5 mol/s
  • Ca to 10 millimols

Question 4

Question
Action potential is shape depends on
Answer
  • Irritation strength
  • Cell type
  • Amount of lipids in the membrane irritated

Question 5

Question
Action potential is
Answer
  • Minimal value of resting potential
  • Maximum value of resting potential
  • None of these

Question 6

Question
Elevation of calcium concentration is for
Answer
  • contraction
  • interruption of action potential
  • relaxion

Question 7

Question
Stable membrane is
Answer
  • phasic sm
  • tonic sm
  • both

Question 8

Question
Average power of contraction of smooth muscle per unit cross section
Answer
  • is smaller than that of striated muscle
  • bilayer
  • equal

Question 9

Question
Actin and myosin are in [blank_start]cellular fiber network[blank_end]
Answer
  • cellular fiber network

Question 10

Question
Smooth muscle cells are organised in [blank_start]bundles[blank_end] in strong parallel layers or spherical structures
Answer
  • bundles

Question 11

Question
Ion channels are
Answer
  • tubular links between cells
  • ionized groove upon the membrane
  • protein structures in membranes through which ions pass

Question 12

Question
Ion channels conductivity during the action potential
Answer
  • has a constant value
  • depends on the level of membrane potential
  • increases logarithimacally over the time

Question 13

Question
On the border water-air (the free surface of the water) lipids from
Answer
  • monolayer
  • three-layered electrically conductive structure
  • lipid gel

Question 14

Question
In stationary state the membrane potential
Answer
  • stays constant if parameters of the system are stable
  • is altered in sinus manner
  • slowly reaches to zero

Question 15

Question
Both smooth muscle contractions and skeletal muscle contractions involve thin (actin) filament over the thick (myosin) filaments
Answer
  • True
  • False

Question 16

Question
In smooth muscle contraction, the majority of calcium (Ca2+) needed for contraction enters from extracellular fluid.
Answer
  • True
  • False

Question 17

Question
Troponin and tropomyosin are attached to thick filaments of smooth muscle cells
Answer
  • True
  • False

Question 18

Question
Myosin of the thick filaments of smooth muscle cells must be phosphorylated in order to bind of the thin filaments
Answer
  • True
  • False

Question 19

Question
Nor-epinephrine released from sympathetic nerve terminals in the heart cause a decrease in the pacemaker activity.
Answer
  • True
  • False

Question 20

Question
The rapid upstoke (phase 0) of actin potentials in ventricular and atrial myocytes results from opening of Ca2+ channels.
Answer
  • True
  • False

Question 21

Question
Thick filaments are composed of myosin and thin filaments are primarily composed of actin.
Answer
  • True
  • False

Question 22

Question
Tropomyosin binds Ca2+ causing a conformational change that causes troponin to uncover binding sites on actin for crossbridge attachment.
Answer
  • True
  • False

Question 23

Question
Nifedine is a
Answer
  • Calcium (Ca2+) channel blocker
  • Sodium (Na+) channel blocker
  • Potassium (K+) channel blocker

Question 24

Question
Tetraethylammonium is a blocker for which channel?
Answer
  • Calcium (Ca2+) channel
  • Sodium (Na+) channel
  • Potassium (K+) channel

Question 25

Question
Verapamil is a
Answer
  • Calcium (Ca2+) channel blocker
  • Sodium (Na+) channel blocker
  • Potassium (K+) channel blocker

Question 26

Question
Which is not a type/class of carrier protein?
Answer
  • Uniport
  • Symport
  • Antiport
  • Microport

Question 27

Question
Ionophores have following action except
Answer
  • Inhibit ADP to ATP conversion
  • Abolish proton gradient
  • Abolish pH gradient
  • Hydrophilic in character

Question 28

Question
Diffusion through a semi-permeable membrane with different permeabilities for different substance is called:
Answer
  • Tran-Diffusion
  • Filtration
  • Osmosis
  • Diffusion

Question 29

Question
The pressure that would have to be applied to a pure solvent to prevent it from passing into a given solution by osmosis
Answer
  • Osmotic Pressure
  • Filtration Pressure
  • Osmotic Stability

Question 30

Question
Movement of liquid across a semipermeable membrane under hydrostatic pressure is called
Answer
  • Filtration
  • Hydrostatic Diffusion
  • Osmosis
  • None of these

Question 31

Question
GLUT1 and Ionophores valiomycin are examples of
Answer
  • Uniport
  • Symport
  • Antiport

Question 32

Question
Antiport is best described by
Answer
  • Carrier protein binds one solutes and transports it across the membrane
  • Carrier protein binds two different solutes and transport them together across the membrane
  • A substrate binds and is transported across the membrane then another substrate binds and is transported in the other direction

Question 33

Question
A factors that does NOT affect rate of facilitated diffusion:
Answer
  • Concentration gradient across the membrane
  • Amount of carrier proteins available
  • Speed of carrier and substrate attachment
  • How fast the protein changes shape after attachment
  • Mean Molecular Velocity

Question 34

Question
Which of these is not a type of ion channel?
Answer
  • Receptor Regulated
  • Membrane Potential-Dependent
  • Ion Regulated

Question 35

Question
Which of this is not a class of ATPase
Answer
  • P-Type
  • F-Type
  • V-Type
  • L-Type

Question 36

Question
Which statement is incorrect?
Answer
  • P-type- transport Na+, K+, Ca2+ through plasma membrane and in doing so they are phosphorylated
  • F-type- found in mitochondria where they are the prime producers of ATP by using the proton gradient generated by oxidative phosphorylation
  • V-type- only found in plant cells, catalysing ATP hydrolysis to transport solutes

Question 37

Question
The downhill (along concentration Gradient) movement of one species driving the uphill (against concentration Gradient) movement of another where metabolic energy is not utilised directly is called
Answer
  • Primary Active Transport
  • Secondary Active Transport
  • None of these

Question 38

Question
Which part of the sodium-potassium pump (Na=/K+ ATPase) has an ATP binding site and 3 other sites which have a high affinity for Na+ ion
Answer
  • the part of the protein that faces the cytoplasm (inner part)
  • the part of the protein that faces extracellular environment (outer part)
  • Both of these

Question 39

Answer
  • Resting Potential
  • Depolarization
  • Repolarization
  • Hyperpolarization

Question 40

Question
The resting potential can be changed by chemical, mechanical or electrical stimulus
Answer
  • True
  • False

Question 41

Question
No refractory period is associated with graded potentials.
Answer
  • True
  • False

Question 42

Question
Quiescent cells
Answer
  • refer to the period when a cell is not dividing
  • refer to the period when a cell is dividing
  • none of these

Question 43

Question
If the membrane potential is changed slowly, the electrical current can pass without action potential needing to be initiated. This phenomena is known as
Answer
  • Accommodation
  • Action Potential
  • Electronic Potential
  • None of these

Question 44

Question
Fill in the gaps: (symbols like K+ /Na+/Ca2+ are used instead of word) Phase 0: Rapid depolarization: [blank_start]increased[blank_end] Na+ and [blank_start]decreased[blank_end] K+ conductances Phase 1: Initial re polarization: decreased [blank_start]Na+[blank_end] and increased [blank_start]K+[blank_end] conductances Phase 2: [blank_start]Plateau phase[blank_end]: increased [blank_start]Ca2+[blank_end] conductance Phase 3: Re-polarization: increased [blank_start]K+[blank_end] and decreased [blank_start]Ca2+[blank_end] conductances Phase 4:[blank_start]Resting potential[blank_end]: [blank_start]increased[blank_end] [blank_start]K+[blank_end] and [blank_start]decreased[blank_end] Na+ and [blank_start]decreased[blank_end] Ca2+ conductance
Answer
  • increased
  • decreased
  • Plateau phase
  • Na+
  • K+
  • Ca2+
  • K+
  • decreased
  • Resting potential
  • increased
  • decreased
  • K+
  • Ca2+

Question 45

Question
What results in a decrease of AP amplitude and depolarization block therefore the heart stops in diastole?
Answer
  • Increased sodium (Na+) extracellularly
  • Increased Potassium (K+) extracellularly
  • Decreased Potassium (K+) extracellularly

Question 46

Question
What results in shortening of the refractory period therefore a defibrilation risk?
Answer
  • Increased extracellular potassium (K+)
  • Decreased extracellular potassium (K+)
  • Increased extracellular calcium (Ca+)

Question 47

Question
What would cause a sudden decrease of AP depolarization phase and its duration resulting in cells becoming unexcitable?
Answer
  • Increased extracellular potassium (K+)
  • Increased extracellular sodium (Na+)
  • Decreased extracellular sodium (Na+)

Question 48

Question
Which of these statements are true More than one correct ans.
Answer
  • Z line – Where the myosin filaments are anchored
  • M line – Where the myosin filaments are anchored
  • A band – The length of a myosin filament, may contain overlapping actin filaments
  • I band – Contains only actin filaments
  • H Zone- Contains only myosin filaments
  • All are true
  • None are true

Question 49

Question
Which is true for Troponin T
Answer
  • Connect troponin to Tropomyosin
  • Suppress interaction between actin and myosin in absence of Ca2+
  • Reversible connection with Ca2+ when concentration of Ca2+ is high enough

Question 50

Question
Which best describes Isometric muscle contraction?
Answer
  • Muscles shortens in length in relationship to the production of movement (i.e. push ups)
  • Muscle length remains the same, no movement occurs but the force (muscle tension) is increased above tonic levels to resist gravity or other forces i.e. holding a shopping bag
  • Contraction against increasing force

Question 51

Question
[blank_start]Isotonic[blank_end]: Muscles shortens in length in relationship to the production of movement (i.e. push ups) [blank_start]Isometric[blank_end]: Muscle length remains the same, no movement occurs but the force (muscle tension) is increased above tonic levels to resist gravity or other forces i.e. holding a shopping bag [blank_start]Auxotonic[blank_end]: Contraction against increasing force
Answer
  • Isotonic
  • Isometric
  • Auxotonic

Question 52

Question
Force<load therefore axotonic/eccentric contraction speed of contraction (V) is
Answer
  • Slow
  • Fast
  • Stays the same

Question 53

Question
Electromechanical connection is the dependence between membrane potential and
Answer
  • The contractile activity (CA)
  • Just the membrane potential
  • None of these

Question 54

Question
How long is the latent period between stimuli and muscle contraction
Answer
  • 2-3 ms
  • 2-3 sec
  • No latent period
  • 12-13 ms
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