O.G Physiology Practice Exam:

A decrease in the absolute value of the membrane potential toward zero is called A. An action potential B. Hyperpolarization C. A membrane potential D. Depolarization

D

A shift of the resting transmembrane potential toward 0 mV is called A. polarization B. Potential difference C. Hyperpolarization D. Depolarization E. Repolarization

D

If the ratio of NAD to NADH2 in a cell is 1 (NAD/NADH2 = 1), the cell is in A. Reduced state B. Oxidative state C. Oxygen Deficiency D. Redox balance

D

Redox balance is the A. gain of electrons B. removal of electrons from a compound without any addition of them C. loss of electrons D. removal of electrons from a compound as quickly as they are added

D

Small mammals need more O2 per gram of body weight than large mammals do. Compared to large mammals, small mammals have _______ lungs and breathe _______ times per minute. A. Smaller; more B. Smaller; fewer C. Bigger; more D. Similar-sized; more

D

The specific dynamic action (SDA) for an animal is measured in an animal that consumes 100 g of carbohydrate. The measurement is repeated a few days later, after the animal has been fed 200 g of protein. How will the magnitude of the second SDA compare with the first SDA measurement? A. it is not possible to estimate without the RQ B. it will be about the same C. it will be about twice as much D. it will be more than twice as much

D

The statement "If an isolated system undergoes internal change, the direction of change is always toward greater disorder" is a description of A. Energy metabolism B. Molecular kinetic energy C. Physiological work D. The second law of thermodynamics

D

The substrate needed to initiate the Krebs cycle is A. Pyruvate B. Glucose C. Citrate D. Acetal coenzyme A

D

Which of the following actively contributes to the cell's membrane potential? A. the overall resistance of the membrane B. Permeability to K+ C. Permeability to Na+ D. Electrogenic ion pumps

D

Which of the following is true about threshold for an action potential? A. voltage gated potassium channels begin to open B. Threshold for a typical neuron is approximately -30mV C. voltage-gated potassium channels begin to close D. it is more positive than the resting membrane potential E. the membrane begins to hyperpolarize

D

Which type of energy cannot be used by animals to do physiological work? A. electrical energy B. mechanical energy C. chemical energy D. heat (molecular kinetic energy)

D

which of the following is an example of an isolated system? A. an individual bacterium in an animal's gastrointestinal tract B. a lone astronaut in the international space station C. an electrically powered pump circulating hot water through an apartment building D. a hypothetical construct in which neither energy nor matter can pass

D

A semipermanent increase in metabolic rate in response to repeatedly eating unusually large amounts food is called A. diet-induced thermogenesis B. Fat-simulated metabolism C. dietary scaling D. The heat increment of feeding

A

At a(n) ________ synapse, a neurotransmitter is released to stimulate the postsynaptic membrane. A. Chemical B. Osmotic C. Gap D. Electrical E. Cell

A

If a P/O ratio is 1.9, oxidative phosphorylation and electron transport are said to be A. produce a temporary graded potential B. produce a very small action potential C. not change the overall membrane potential at all D. produce an action potential

A

Neurons that relay sensory signals to integrative centers of the CNS are called A. afferent neurons B. efferent neurons C. interneurons D. synaptic neurons

A

Puffer fish poison blocks voltage-gated sodium channels like a cork. What effect would this neurotoxin have on the function of neurons? A. The axon would be unable to generate action potentials B. neurons would depolarize more rapidly C. the absolute refractory period would be shorter than normal D. action potentials would lack a repolarization phase E. none, because the chemically gated sodium channels would still function

A

The enzyme _______ is required to convert glucose to glucose-6-phosphate A. Hexokinase B. Phosphofructokinase C. Isomerase D. Pyruvate kinase

A

The final electron acceptor of the electron transport chain is A. oxygen B. NAD C. glucose D. water

A

The increase in the metabolic rate of an animal that results from eating food is called A. Specific dynamic action B. Diet induced thermogenesis C. Aerobic metabolism D. Material balance

A

The presence of ________ dramatically increases the speed at which an action potential moves along an axon. A. Myelin B. Neurilemma C. Glial cells D. A capsule E. Plasma protein

A

The sum of the electrical and chemical forces acting on an ion is known as its A. electrochemical gradient B. Action potential C. Summation difference D. Thermodynamic difference E. Permeability gradient

A

The term "weight-specific metabolic rate" refers to A. whole-animal metabolic rate divided by body weight B. the change in metabolic with bodyweight C. whole-animal metabolic rate multiplied by the mass D. whole-animal metabolic rate at a specific body weight

A

To escape from a predator, a fish most likely uses _______ muscles. A. Fast glycolytic B. Slow oxidative C. A combination of oxidative and glycolytic D. Fast glycolytic first and after few seconds slow oxidative

A

Which protein does not participate in proton movement? A.succinate dehydrogenase B. cytochrome b-c1 C. ATP synthase D. cytochrome oxidase

A

Which statement most accurately summarizes the chemiosmotic hypothesis? A. protons move from low concentration to high concentration, creating unequal distribution across the inner mitochondrial membrane B. a phosphate group moves from ATP to another substrate C. hydrogen ions are pumped into the matrix to create an electrochemical gradient D. electrons are transferred along the electron transport chain and delivered to oxygen

A

A threshold stimulus is the A. hyperpolarization of an axon B. depolarization necessary to cause an action potential C. peak of an action potential D. electrical current that crosses the synaptic cleft E. resting membrane potential

B

Animals need _______ to create and maintain internal organization. A. Heat B. Energy C. An open system D. Entropy

B

Catabolic processes _______ and anabolic processes _______. A. use energy to build molecules; break down organic molecules to release energy B. break down organic molecules to release energy; use energy to build molecules C. use energy to break down molecules; use energy to build molecules D. use energy to break down all molecules; break down organic molecules

B

Graded potentials A. produce an effect that increases with distance from the point of stimulation B. may be either depolarization or a hyperpolarization C. produce an effect that spreads actively across the membrane surface D. Cause repolarization E. Are often all-or-none

B

In which case would the equation M =aWb not be considered allometric? A. a=1 and b equals any value B. b=1 and a equals any value C. a=1 and b<1 D. a=1 and b>1

B

Larger mammals need more oxygen than smaller mammals, but they need less oxygen per gram of body weight. Smaller mammals meet their need for more oxygen with a _______ mass-specific heart size and a _______ heart rate. A. Bigger; faster B. Similar; faster C. Smaller; faster D. Bigger; slower

B

Protons are transferred back to the mitochondrial matrix via A. Succinate dehydrogenase B. ATP synthase C. Cytochrome b-c1 D. Cytochrome oxidase

B

Slow oxidative muscle fibers are used during A. sprinting B. jogging C. weight lifting D. speed skating

B

Specific conditions must apply when either basal or standard metabolic rate is being measured. The animals must be A. measured at standard temperature and pressure B. fasting C. fed a standard diet D. fully grown

B

Suppose you eat five cookies, each of which contains 100 calories. If the same amount of energy in the cookies was used to heat 50,000 g of water, the temperature of the water would increase by A. 1.0 C B. 10 C C. 0.1 C D. 100 C

B

What is different between the heat resulting from a fire and the heat produced by animals? A. the heat that animals obtain from food is always less than heat obtained from burning food in a fire B. there is no difference C. heat from animals results from internal work and heat from a fire comes from external work D. energy from fires always produce heat, but energy use by animals does not always generate heat

B

Which factor exerts a particularly large effect on metabolic rates? A. Environmental O2 level B. Environmental temperature C. Time of day D. Age

B

Which statement regarding the action potential is false? A. in the recovery phase, Na+ channels are closed B. in an extremely long axon, the action potential eventually will degrade C. during the "falling phase", K+ permeability increases

B

Which type of synapse is most common in the nervous system? A. Electrical B. Radiative C. Chemical D. processing E. Mechanical

B

Suppose an animal is oxidizing food according to the following reaction:C16H32O2 + 23 O2 → 16 CO2 + 6 H2O + 10,042 kJ/mol. What is the respiratory quotient? A. 10,042/23 B. 10,042/16 C. 16/23 D. 23/16

C

Suppose an animal is oxidizing food according to the following reaction:C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + 2820 kJ/mol. What is the respiratory quotient? A. 18 B. 2820 C. 1 d. 6

C

The following are the main steps in the generation of an action potential. 1. Sodium channels are inactivated. 2. Voltage-gated potassium channels open and potassium moves out of the cell, initiating repolarization. 3. Sodium channels regain their normal properties. 4. A graded depolarization brings an area of an excitable membrane to threshold. 5. A temporary hyperpolarization occurs. 6. Sodium channel activation occurs. 7. Sodium ions enter the cell and depolarization occurs. A. 4, 2, 5, 6, 7, 3, 1 B. 2, 4, 6, 7, 1, 3, 5, C. 4, 6, 7, 1, 2, 3, 5 D. 4, 6, 7, 3, 2, 5, 1 E. 6, 7, 4, 1, 2, 3, 5

C

The specific dynamic action (SDA) is measured for an animal that eats 100 g of protein. The measurement is repeated a few days later, after the animal has been fed 300 g of protein. According to the usual model of SDA, how will the magnitude of the second SDA compare with the first SDA measurement? A. It will be more than three times as much B. It is not possible without the RQ C. It will be about three times as much D. It will be about the same

C

What would happen to energy production if NADH and FADH2 were not available? A. the Krebs cycle would stop B. oxygen would become unavailable C. the electron transport chain would stop D. glycolysis would continue

C

When potassium channels open and the ions diffuse through the membrane A. the membrane will depolarize to threshold B. there will be almost no effect on tranmembrane potential C. the inside of the membrane will become more negative D. the inside of the membrane will become more positive E. the membrane will become depolarized

C

_______ channels govern the generation of an action potential. A. voltage-gated K+ B. ligand-gated Na+ C. Voltage-gated Na+ D. ligand-gated K+

C

A neuron that receives neurotransmitter from another neuron is called A. a satellite cell B.an oligodendrocyte C. the presynaptic neuron D. the motor neuron E. the postsynaptic neuron

E

Any stimulus that opens a ________ ion channel will produce a graded potential. A. voltage-gated B. mechanically gated C. sodium D. chemically gated E. all of the answers are correct

E

At a(n) ________ synapse, a neurotransmitter is released to stimulate the postsynaptic membrane. A. Cell B. Electrical C. Gap D. osmotic E. Chemical

E

Ions can move across the plasma membrane in which of the following ways? A. through passive or leak channels B. through chemically gated channels as in neuromuscular transmission C. through voltage-gated channels as in the action potential D. by ATP-dependent ion pumps like the sodium-potassium exchange pump E. all of the answers are correct

E

Aerobic substrate-level phosphorylation produces a total of _______ ATP molecules per glucose molecule. A. 2 B. 6 C. 29 D. 31

b