Cell: The Unit of Life Questions and Answers

Which of the following best explains the relationship between catabolic and anabolic chemical reactions in a metabolic pathway A B C D Catabolic reactions use energy to make more complex molecules whereas anabolic re actions produce energy and break down molecules into simple complexes Both catabolic and anabolic reactions make simple compounds however catabolic re actions produce energy whereas anabolic reactions use energy Catabolic reactions release energy by breaking down complex molecules into simpler compounds whereas anabolic reactions consume energy and make more complex mol ecules from simpler ones Both catabolic and anabolic reactions use simple compounds to make more complex molecules however anabolic reactions do not use energy whereas catabolic reactions do

Artificially induced apoptosis controlled cellular death is found to be an effective treat ment for some forms of cancer Which of the following describes the most likely mechanism by which apoptosis might be induced A B C D by causing lysosomes to release digestive enzymes into the cytosol by causing ribosomes to increase the rate of protein synthesis by triggering the division of mitochondria in the cell to increase ATP production by increasing the expression of membrane bound glucose protein channels

The plasma membrane model below shows two proteins in their inactive and active states Membrane Transport A B C extracellular space D OO protein 1 intracellular space According to the diagram which is the most likely function performed by protein 2 200 JD transporting a small neutral particle across the cell membrane via active transport transporting an ion across the cell membrane via active transport ATP transporting an ion across the cell membrane via facilitated diffusion transporting a small neutral particle across the cell membrane by simple diffusion protein 2

Carbon dioxide most likely enters a cell through which of the following processes A active transport through membrane proteins B C D simple diffusion through the membrane active transport through aquaporins facilitated diffusion through membrane proteins

Indicate which of the following is characteristic during a Resting Potential Greater concentration outside of cell Greater concentration inside of cell Difference in charge across membrane Sodium Potassium Pump collects 2 of these ions for each 3 of the other type that it ejects Na K 70mV Na

m 10 points The functions of the cell envelope include Check All That Apply Helping to determine the shape of a bacterial cell Preventing rupture of the cell from increased interna

25 In resting condition free Ca ions a Are accumulated in cytoplasm b Are accumulated in sarcoplasmic reticulum in nucleus in mitochondria c Are accumulated d Are accumulated

18 What is Saltatory conduction of nerve impulse A Saltatory conduction is the propagation of action potentials along myelin increasing the conduction velocity of action potential b Saltatory conduction is the propagation of action potentials along myelindecreasing the conduction velocity of c d b c Saltatory conduction is the propagation of action potentials along myelinated axons from one node of Ranvier to the next node increasing the conduction velocity of action potential Salunory conduction is the propagation of action potentials along myelinated axons from one node of Ranvier to the next node decreasing the conduction velocity of action potential 19 During first phase of action potential Depolarization Permeability of ions is not changing Permeability for K and Cl ions decreases for Na stays the same Permeability for K and Cl ions stayes the same for Na ions increases Permeability for K and Na ions stayes the same for C1 ion decreases

a b c d 4 Hyperpolarization is caused by Potassium ions Sodium ions Hydrogen ions Chlorine ions 5 During refractory period a Potassium and Sodium ion channels are open b Sodium voltage gated channels are closed c The refractory period of a neuron is the time in which a nerve cell is unable to fire an action potential impulse d Potassium voltage gated channels are open

7 Which ion channels are open during depolarization phase

7 Which ion channels are open during depolarization phase

a b c d 21 Which of the following statement is correct Membrane resting potential potential difference between membrane surfaces caused by selective permeability of the membrane and separation of charges Membrane resting potential is equal distribution of charges Membrane resting potential potential difference between membrane surfaces caused by selective permeability of the membrane and equal distribution of charges Membrane resting potential is depolarized state of the membrane 22 Importance of refractory period consists in one of the following It links impulses of irritation together and provides propagation of a neural impulse in both directions Prevents overlap of neural impulses and provides propagation of neural impulse in only one direction from Excited site to resting site Blocks impulses of irritation in both directions Provides propagation of impulses of irritation through the axon in both directions

in bot 23 Equilibrium potential b c a Stops net movement of ions across the membrane down the electrochemical gradient Causes the movement of ions across the membrane against the concentration gradient Initiates the movement of ions across the membrane down the concentration gradient Initiates the movement of ions across the membrane against the concentration gradient d 24 Capacitive and Ohm s resistance of the membrane causes a Equal distribution of charges across the membrane generation of electric gradients and potential differences across the membrane possible modulation of membrane potential b Unequal distribution of charges across the membrane generation of electric gradients and potentiall difference across the membrane possible modulation of membrane potential c Equal distribution of charges across the membrane generation of electric gradients and potential difference across the membrane possible propagation of membrane potential d Unequal distribution of charges across the membrane generation of electric gradients and potentia difference across the membrane possible propagation of membrane potential

a b 3 Size of the charge b Permeability of cations tege a d c d 4 Diffuse potential depends on 5 Electrogenic pumps a They do not contribute in the formation of transmembrane potential They participate in the formation of transmembrane potential Maintain only concentration gradient b They increase transmembrane potential Permeability of anions Permeability of cations and anions 6 What are conditions for Donnan equilibrium Donnan equilibrium takes into account electroneutrality sum of permeable ion concentrations are equal the both sides of membrane In physiological conditions intracellular and extracellular compartments are in equilibrium conditions Donnan equilibrium takes into account electroneutrality multiplication of permeable ion concentrations equal on the both sides of membrane Donnan equilibrium takes place when membrane is permeable for large organic molecules impermeable for nonorganic ions

b c d a coge b c d 5 1 What determines potential difference Stored energy in the cell Current in the membrane Summarized membrane resistance Osmotic balance 2 Ionic current in the membrane is positive if Cations move out the cell Anions move into the cell Cations move into the cell Anions move out the cell 3 Nerast equation is correct for Only for ions in equilibrium state Only for ions in non equilibrium state For ions in equilibrium and nonequilibrium state For permeable ions

a b c d 8 Threshold stimulus causes Activation of K non gated channels Rapid activation of K voltage gated channels Rapid activation of Na voltage gated channels Rapid inactivation of Na voltage gated channels 9 Which of the following statements is true a Membrane permeability to K ions in a living cell is 50 100 times lower than permeability to Na ions in absence of K ions in the surrounding area membrane permeability to these ions will be very high D Membrane permeability to K ions in a living cell is 50 100 times higher than permeability of Na ions in bsence of K ions in the surrounding area membrane permeability to these ions will be very high Membrane permeability to K ions in a living cell is 50 100 times higher than permeability of Na ic though with the lack of K ions in the surrounding area membrane conductivity to these ions will be very lo Membrane permeability to K ions in a living cell is 50 100 times lower than permeability of Na ions in absence of K ions in membrane surrounding area membrane permeability to these ions will be very low