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

Membrane potential operated channels are

Striated muscle are structure bases of

Muscle extraction is possible when

Action potential is shape depends on

Action potential is

Elevation of calcium concentration is for

Stable membrane is

Average power of contraction of smooth muscle per unit cross section

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

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

Ion channels are

Ion channels conductivity during the action potential

On the border water-air (the free surface of the water) lipids from

In stationary state the membrane potential

Both smooth muscle contractions and skeletal muscle contractions involve thin (actin) filament over the thick (myosin) filaments

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

Troponin and tropomyosin are attached to thick filaments of smooth muscle cells

Myosin of the thick filaments of smooth muscle cells must be phosphorylated in order to bind of the thin filaments

Nor-epinephrine released from sympathetic nerve terminals in the heart cause a decrease in the pacemaker activity.

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

Thick filaments are composed of myosin and thin filaments are primarily composed of actin.

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

Nifedine is a

Tetraethylammonium is a blocker for which channel?

Verapamil is a

Which is not a type/class of carrier protein?

Ionophores have following action except

Diffusion through a semi-permeable membrane with different permeabilities for different substance is called:

The pressure that would have to be applied to a pure solvent to prevent it from passing into a given solution by osmosis

Movement of liquid across a semipermeable membrane under hydrostatic pressure is called

GLUT1 and Ionophores valiomycin are examples of

Antiport is best described by

A factors that does NOT affect rate of facilitated diffusion:

Which of these is not a type of ion channel?

Which of this is not a class of ATPase

Which statement is incorrect?

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

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

Label Image

The resting potential can be changed by chemical, mechanical or electrical stimulus

No refractory period is associated with graded potentials.

Quiescent cells

If the membrane potential is changed slowly, the electrical current can pass without action potential needing to be initiated. This phenomena is known as

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

What results in a decrease of AP amplitude and depolarization block therefore the heart stops in diastole?

What results in shortening of the refractory period therefore a defibrilation risk?

What would cause a sudden decrease of AP depolarization phase and its duration resulting in cells becoming unexcitable?

Which of these statements are true More than one correct ans.

Which is true for Troponin T

Which best describes Isometric muscle contraction?

[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

Force<load therefore axotonic/eccentric contraction speed of contraction (V) is

Electromechanical connection is the dependence between membrane potential and

How long is the latent period between stimuli and muscle contraction