Exam 1 Sample & Homework Questions
A normal red blood cell will shrink in size when places in a solution of: 100 mM CaCl2 100 mM NaCl 150 mM NaCl 400 mM glucose
400 mM glucose
In which of the following solutions would cells normally swell and burst? 150 mM NaCl + 100 mM glucose 100 mM NaCl + 100 mM glucose 50 mM NaCl + 200 mM glucose 50 mM NaCl + 100 mM glucose
50 mM NaCl + 100 mM glucose (see second half of lecture 3. Bursting = hypotonic solution = solution lower than the cell. 300 = isotonic. Osmolarity: glucose is 1:1, NaCl is 2 because you count Na and Cl separately)
Alexis weighs about 100 lbs. How much of her total body weight is water? 20 lbs 40 lbs 50 lbs 60 lbs
60 lbs (60-40-20 rule: 60% total body weight is water, 40% intracellular, 20% extracellular (80% of which is interstitial/surrounding tissues and 20% is blood plasma)
Osmosis requires: A concentration gradient of solutes across a semipermeable membrane Simultaneous active transport of ions A membrane more permeable to solute than water A breakdown of ATP
A concentration gradient of solutes across a semipermeable membrane (water going down concentration gradient through aquaporin channel proteins)
One example of an integral protein is: A voltage-gated channel A neurotransmitter Ribosomal RNA Ribosomal enzymes
A voltage-gated channel
The figure (left side: 9 water and 12 solute, right side: 14 water and 5 solute) shows a container with an impermeable membrane (hashed line) separating the left compartment and the right compartment. What direction would the membrane move is aquaporin channels were placed in the membrane? What direction would the membrane move if both aquaporin channels and carrier proteins for the solute were in the membrane? Neither, left Right, neither Left, neither Neither, right
Membrane to the right, neither (3/4 through lecture 3. aquaporin = solute does not move across the membrane but water moves down concentration gradient so membrane would have to move to reach equilibrium. both aquaporin and carrier proteins = both solute and water move down concentration gradient bilaterally so the membrane doesn't need to move to help reach equilibrium due to solute not being able to move)
The supporting cells which are responsible for removing microbes and foreign pathogens within the CNS are the... Schwann cells Microglia Oligodendrocytes Astrocytes Neuron
Microglia
Which of the following cytoskeletons act as a scaffold to determine cell shape and movement of cell organelles and vesicles? Microfilament (e.g. actin) Microtubules (e.g. tubulin) Thick filament myosin Intermediate filament (e.g. keratin)
Microtubules (e.g. tubulin)
______ only develop into a limited number of cell types within a lineage (endoderm, mesoderm, or ectoderm), whereas ____ can develop into a person Multipotent stem cells, pluripotent stem cells Pluripotent stem cells, totipotent stem cells Multipotent stem cells, totipotent stem cells Totipotent stem cells, embryonic stem cells
Multipotent stem cells, totipotent stem cells
These cells are excitable and generate action potentials Connective tissue cells Epithelial cells Totipotent stem cells All of these cells are excitable Muscle cells
Muscle cells
Homeostasis of the body is maintained by ____. Which process if regulated by this mechanism? Negative feedback mechanisms, blood clotting Positive feedback mechanisms, regulation of body temperature Negative feedback mechanisms, regulation of body temperature Positive feedback mechanisms, opening of voltage-gated Na+ channels
Negative feedback mechanisms, regulation of body temperature
Gray matter is primarily composed of... Myelin Postganglionic neuron cell bodies Myelinated axons Neuronal and glial cell bodies
Neuronal and glial cell bodies
Which of the following receptors are ionotropic? Beta-antagonist receptors Muscarinic receptors Nicotinic receptors Voltage-gated Na+ channels Alpha-adrenergic receptors
Nicotinic receptors
The process of transcription of eukaryotes occurs in the: Lysosome Nucleus Ribosome Golgi apparatus Cytosol
Nucleus
Which structure has a double membrane consisting of two separate lipid bilayers? Plasmalemma Ribosome Lysosome Nucleus Peroxisome
Nucleus
Which of the following is maintained at the same level between the interstitial fluid and intracellular fluid? K ion concentration Ca ion concentration Na ion concentration Osmolarity
Osmolarity
_____ diffuse(s) directly through the phospholipid bilayer of cell membranes, whereas ____ do(es) not directly diffuse through the phospholipid bilayer of cell membranes Fatty acids, carbon dioxide Amino acids, steroid hormones Sodium, potassium Oxygen, glucose Water, calcium Carbon dioxide, fatty acids
Oxygen, glucose (can diffuse: gases, fatty acids, steroids - can't diffuse: hydrophilic/polar molecules, water, proteins, amino acids, glucose, Na+, Ca++, Cl-, K+)
Oxygen moves through the plasma membrane by: Facilitated diffusion Passive diffusion Active transport Vesicle-mediated transport
Passive diffusion (gases always use simple diffusion)
Which of the following cell organelles is responsible for detoxification of toxic molecules? Peroxisome Golgi apparatus Endoplasmic reticulum Lysosome
Peroxisome (membrane bound sacs which contain enzymes that break down toxins. lysosomes contain enzymes that break down old organelles)
White blood cells engulf bacteria through the process of _____, and the bacteria are broken down in the cell's ______ Pinocytosis, lysozone Exocytosis, mitochondria Phagocytosis, lysosome Receptor endocytosis, Golgi
Phagocytosis, lysosome
23. Norepinephrine will bind to: A. Beta1 adrenergic receptors B. nicotinic receptors C. cholinergic receptors D. muscarinic receptors
A. Beta1 adrenergic receptors
26. Acetylcholine: A. can be either excitatory or inhibitory. B. binds to adrenergic receptors. C. is the only transmitter used by the autonomic nervous system. D. is released by all postganglionic neurons.
A. can be either excitatory or inhibitory.
25. A drug classified as a "beta blocker" (an antagonist of a beta1 receptor on an effector tissue) would be expected to: A. decrease blood pressure B. decrease GI secretions C. increase the force of heart muscle contraction D. relax bronchial muscle
A. decrease blood pressure
30. The neurotransmitter released by the postganglionic parasympathetic neuron usually binds to a(n): A. muscarinic cholinergic receptor B. nicotinic cholinergic receptor C. alpha adrenergic receptor D. beta adrenergic receptor
A. muscarinic cholinergic receptor
28. During the hyperpolarization phase of an action potential: A. voltage-gated Na+ channels are closed and voltage-gated K+ channels are open B. voltage-gated Na+ channels are open and passive K+ channels are open C. voltage-gated Na+ channels are closed and passive K+ channels are closed D. voltage-gated Na+ channels are open and voltage-gated K+ channels are open
A. voltage-gated Na+ channels are closed and voltage-gated K+ channels are open
All of the motor neurons (somatic or autonomic) that come directly from the CNS release which neurotransmitter? Dopamine Norepinephrine Acetylcholine Glutamate Epinephrine
Acetylcholine
Na+: Often diffuses through a pore May diffuse through voltage-gated Na channel May bind to a Na+/K+ ATPase to be transported against the concentration gradient A & B A, B, & C
All
Which of the following components is not a part of a basic homeostatic control loop? Variable Amplifier Sensor Integrating center Effector
Amplifier
Which of the following would result in the depolarization of a neuron? An increase in the number of K+ leak channels in the neuron membrane A spatial summation of two inhibitory post-synaptic potentially An increase in extracellular K+ concentration Decreasing the number of voltage-gates Na+ channels
An increase in extracellular K+ concentration (if the external charge is increasing, action potential is going to start because potassium is going to want to be coming into the cell via concentration gradient)
The concept of homeostasis: Applied to individual cells as well as the whole body Indicates that you can stay inside when it is cold outside Implies that conditions within the body are maintained completely/rigidly constant Always employ positive feedback
Applied to individual cells as well as the whole body
The region of a neuron typically associated with the generation of an action potential is the Synapse Axon hillock Dendrite Soma
Axon hillock
The region of a neuron typically associated with the generation of an action potential is the: Synapse Axon hillock Dendrite Soma
Axon hillock
The C line (gradually increasing flux into cell as extracellular solute concentration increases, then plateau) is most likely described as the flux of ____ into the cell Gasses like oxygen Ions through an open ion channel Polar molecules like glucose Steroid hormones
Polar molecules like glucose
The opening of voltage-gated NA+ channels is a good example of a: Negative feedback mechanism Neutral feedback mechanism Positive feedback mechanism
Positive feedback mechanism
Which of the following is not a function attributed to astrocytes? Controlling blood flow via their end-feet Maintenance of extracellular ion balance Production of CSF Providing metabolic support to the neurons Repair and scarring process of the brain following injury
Production of CSF
12. Which phase of the action potential is associated with opening of the voltage-gated Na+ channels? A. resting state B. slow rising phase C. hyperpolarization D. repolarization E. rapid rising phase
Rapid rising phase
Cells of the adrenal gland medulla: Make and release mineralocorticoids Release epinephrine into the circulation Have muscarinic receptors Are sensory neurons Are modified pre-ganglionic neurons
Release epinephrine
14. Which phase of the action potential is associated with closing of the voltage-gated Na+ channels and opening of the voltage-gated potassium channels? A. resting state B. slow rising phase C. rapid rising phase D. repolarization
Repolarization
21. The two main features of long distance communication in neurons are: A. Morphological and functional asymmetry AND Bidirectional signaling B. Morphological and functional asymmetry AND Unidirectional signaling C. Morphological and functional symmetry AND Bidirectional signaling D. Morphological and functional symmetry AND Unidirectional signaling
B. Morphological and functional asymmetry AND Unidirectional signaling
19. Which of the following statements is TRUE? A. action potentials travel via decremental conduction B. The speed of conduction of action potentials is decreased by demyelinating diseases. C. Myelin is found concentrated in the Nodes of Ranvier D. Graded potentials are conducted without decrement
B. The speed of conduction of action potentials is decreased by demyelinating diseases.
The process of translation in eukaryotes occurs in the: Lysosome Nucleus Ribosome Golgi apparatus Cytosol
Ribosome (DNA turning to RNA through transcription, then RNA (+U in genetic code) to protein/amino acid is translation)
18. The sympathetic nervous system: A. serves the function of "rest or digest". B. has preganglionic neuronal cell somas in the thoracic and lumbar spinal cord. C. has postganglionic neuronal effector cells in the craniosacral spinal cord D. is turned off whenever the parasympathetic nervous system is turned on.
B. has preganglionic neuronal cell somas in the thoracic and lumbar spinal cord.
The process of translation would be most likely to be associated with the: Nucleus Lyzosome Ribosome Mitochondria
Ribosome (site of protein synthesis, occurs in the cytosol with amino acids)
The _____ is responsible for making a peptide/protein by using _____ as a template Ribosome, mRNA Ligase, rRNA Polymerase, DNA Helicase, tRNA
Ribosome, mRNA (dna and dna polymerase is for replication of dna, there's also rna polymerase for transcription from dna to mrna, helicase unwinds the chromosome in replication)
Glucose is transported by glucose transporters, membrane carrier proteins. Which of the following characteristics limits the max rate of glucose transport? Competition Saturation Diffusion coefficient Specificity
Saturation (limited number of carrier proteins to take it across the membrane so it slows down and catches up but doesn't stop)
Select the correct statement comparing active and passive transport Both processes require a concentration gradient as the driving force Only passive transport can move substances against a concentration gradient Both processes require a direct expenditure of energy in the form of ATP Both processes can involve carrier molecules Only active transport occurs paracellularly
Both processes can involve carrier molecules
In a homeostatic control mechanism, which component monitors the controlled variable? Effector Integrating center Sensor Inverter
Sensor
Chemoreceptors are an example of what type of neuron? Limbic Autonomic Sensory Thalamic Spinal
Sensory
Fever is an example of a change in the: Sensor Efferent pathway Afferent pathway Set-point
Set-point
A major site for steroid and lipid synthesis is in the: Mitochondria Ribosome Smooth ER Golgi
Smooth ER (also stores calcium in some cell types like muscles)
Which of the following proteins is NOT an integral membrane protein? Membrane receptor Ion channel Steroid receptor Na+/K+ ATPas (NA/K pump)
Steroid receptor
An increase in heart rate, pupil size, and sweaty palms suggest which of the following? An increase in sympathetic nerve activity An increase in somatic motor nerve activity An increase in nociceptor nerve activity An increase in parasympathetic nerve activity
Sympathetic nervous system
A small hydrophobic molecule such as a steroid hormone would likely cross the plasma membrane: By diffusion through a chemically-gated channel By facilitated diffusion By passive diffusion By active transport By independent carrier molecule
By passive diffusion (can diffuse: gases, fatty acids, steroids - can't diffuse: hydrophilic/polar molecules, water, proteins, amino acids, glucose, Na+, Ca++, Cl-, K+)
Which panel corresponds to 100 mOsm, 200 mOsm, 400 mOsm, or 500 mOsm?
The more shriveled, the higher the mOsm/hypertonic
16. Sodium-potassium ATPase activity on the neuronal membrane results in the movement of: A. (3) Na+ ions out of cell; (3) K+ ions into the cell B. (3) K+ ions out of cell; (2) Na+ ions into the cell C. (3) Na+ ions out of cell; (2) K+ ions into the cell D. (2) K+ ions out of cell; (1) Na+ ions into the cell
C. (3) Na+ ions out of cell; (2) K+ ions into the cell
29. Which of the following statements is FALSE? A. The nervous system is important for rapid communication. B. Communication involves both electrical and chemical transmission. C. The nervous system is the only communication system in the body. D. The process of diffusion is important for function of neurons. E. Dr. Johnson gets excited about neuroscience
C. The nervous system is the only communication system in the body.
20. Neurotransmitters: A. are cholinergic by definition B. "jump" across the motor gap junction C. cross the synaptic cleft by diffusion D. are released from postsynaptic terminals E. are essential for electrical synapses
C. cross the synaptic cleft by diffusion
27. An increase in the extracellular potassium concentration would be expected to result in: A. repolarization B. hyperpolarization C. depolarization D. no change in the resting membrane potential
C. depolarization
17. Which of the following is TRUE of the sodium-potassium pump? A. it pumps Na+ and K+ down their concentration gradients B. it uses facilitated diffusion C. it results in a net loss of positive charges from inside the cell D. it is a voltage-gated transporter
C. it results in a net loss of positive charges from inside the cell
22. As the strength of a depolarizing (excitatory) stimulus to an axon is increased, A. the amplitude of action potentials increases. B. the duration of the action potential increases. C. the frequency of action potentials increases. D. the speed of conduction of the action potential increases.
C. the frequency of action potentials increases.
The phenomenon of saturation is observed in: Passive channels Carrier mediated transport Endocytosis Osmosis
Carrier mediated transport (molecules too big or too polar to cross the cell membrane by simple diffusion need carrier proteins to take them across. Saturation = too few carriers to take lots of molecules across so it slows down)
The basic units of biologic structure and function are: Cells Molecules Tissues Organ systems Organelles
Cells
The part of the brain associated with motor and procedural learning is the... Cerebellum Cranial nerves Autonomic nervous system Brain stem Thoracolumbar spinal cord
Cerebellum
The equilibrium potential is the precise balance between which two opposing forces? Concentration gradient and diffusion Electrochemical and chemomagnetic Electrical potential and equilibrium transfer Chemical diffusion and electrical gradient
Chemical diffusion and electrical gradient
24. Transmembrane proteins that are always open for the movement of ions, but may show some specificity for the type of ion that will pass through them are: A. microtubules B. voltage-gated channels C. chemically-gated channels D. passive ion channels
D. passive ion channels (ion specificity based on diameter of pore, are gated)
A drug that inhibits the Na+/K+ ATPase (Na/K pump) would lead to a(n) _____ to the transport of glucose ______ the cell via the Na+-glucose co-transporter Increase, out of Increase, into Decrease, out of Decrease, into
Decrease, into (B is simple diffusion, C is facilitated, A is steeper than simple)
Which of the following is the primary area of a neuron that received excitatory or inhibitory inputs? Cell soma Dendrites Presynaptic receptors Myelinated sections of the axon
Dendrites
Sodium-potassium ATPase activity in a neuronal membrane: Depends on its presence as an integral membrane molecule Has a small positive influence on the resting membrane potential Is usually maximum Is an example of a positive feedback cycle
Depends on its presence as an integral membrane molecule
The resting membrane potential of a typical neuron is About -55 mV Close to the equilibrium potential of Na+ Due to the characteristics of the membrane Results from a higher extracellular potassium concentration than intracellular
Due to the characteristics of the membrane
Which of the following is an example of active transport? Endocytosis Movement of glucose via the glucose transporter Movement of a steroid hormone through the plasma membrane Movement of sodium ion via the sodium channel
Endocytosis
Which of the following support cell types are found in the PNS? Oligodendrocytes Schwann cells Ependymal cells Ganglia Astrocytes
Ependymal cells
This cell type lines body surfaces and regulates movement of molecules in or out of the body Neuron cells Muscle cells Connective cells All of the answers could be correct Epithelial cells
Epithelial cells
The process of moving a very large molecule out of the cell soma is best described as: Endocytosis Diffusion Exocytosis Phagocytosis
Exocytosis
The process whereby large molecules (the content in vesicles) are released from cells is known as: Phagocytosis Pinocytosis Endocytosis Exocytosis
Exocytosis
The blood plasma is an ___ fluid, and there is ____ plasma than interstitial fluid Extracellular, more Extracellular, less Intracellular, more Intracellular, less
Extracellular, less
As the strength of an excitatory stimulus to an axon increased, The speed of conduction of the action potential increases The duration of the action potential increases The amplitude of the action potential increases The frequency of the action potential increases
Frequency increases
Negative feedback is ____ for homeostasis, and homeostasis _____ require energy Good, does Bad, does Good, does not Bad, does not
Good, does
Human pluripotent stem cells: Are found in adult humans Are fully differentiated at the time of birth Have 23 chromosomes Have a potential to become any cell type
Have a potential to become any cell type
The concept of homeostasis: Usually includes positive feedback as part of the control cycle Is a fundamental to control of the external environment Implies that conditions within the body show little change Is relatively unimportant in physiology
Implies that conditions within the body show little change
The rate of diffusion of potassium through a cell membrane would increase by: Increasing the surface area of the membrane Decreasing the intracellular concentration Decreasing the temperature Decreasing the permeability of the membrane to chloride
Increasing the surface area of the membrane
A homeostasis in the body is maintained by: The negative feedback closed loop The negative feedback open loop The positive feedback closed loop The positive feedback open loop
The negative feedback closed loop (what's the difference between closed and open loops?)
After eating a meal, blood glucose levels cause beta cells in the pancreas to release insulin. Insulin acts on muscle, liver, and fat cells to take up glucose and return blood glucose levels to set-point levels. In this feedback loop, the efferent signal is _______; the initiating signal is ______; the sensor/receptor is _____. Glucagon, blood glucose levels, cells that take up glucose Cells that take up glucose, blood glucose levels, pancreatic beta cells Insulin, blood glucose levels, pancreatic cells Glucose levels, insulin, cells that take up glucose
Insulin, blood glucose levels, pancreatic cells
Channels, receptors, and carriers are: Integral proteins Peripheral proteins Phospholipids Carbohydrates
Integral proteins
Which statement best describes an action potential? No minimum potential required to initiate Usually occurs in dendrites/cell body It can be excitatory or inhibitory Is always the same (all or none), cannot be summed
Is always the same (all or none), cannot be summed
The osmolarity of a solution containing 1 kg (~1 L) of water and 100 mM CaCl2 would be: Hypotonic Hypertonic Isotonic
Isotonic (isotonic = 300. CaCl2 = 3)
The Na/K ATPase contributes to the resting membrane potential (typically negative) because: An equal number of Na ions are moved out for every K ion that is moved in Both Na and K ions are pumped out of the cell There is a constant sodium but not potassium leak into the cell It is electrogenic Both ions are moved against their concentration gradient
It is electrogenic
If a cell in normal physiological conditions has a resting cell membrane potential of -75 mV, which of the following is true? It is primarily permeable to Na+ It is primarily permeable to K+ It is primarily permeable to Ca++
It is primarily permeable to K+
The plasma membrane is: A lipophilic structure Largely made of phospholipids A hydrophilic structure Devoid of proteins
Largely made of phospholipids
Rapid infusion of hyposmotic solution into a vein would be expected to: Have no effect Result in crenation of red blood cells Increase the osmolarity of the blood Lead to lysis of blood cells
Lead to lysis of blood cells
The membrane is impermeable to the solute. If aquaporin channels were placed in the membrane, what direction would the water move? What direction would the membrane move? (left side: 9 water and 12 solute, right side: 14 water and 5 solute) Right, right Left, right Right, right Left, left
Left, right (impermeable to the solute so membrane must move to get equilibrium. water can move down concentration gradient. membrane would move to the R because more molecules are on the L and solute can't move so the membrane would move to get equilibrium)
The hippocampus is part of which relevant brain region and is primarily associated with which function? Brain stem, regulation of basic physiologic functions Limbic system, fear and aggression Thalamus, information processing Limbic system, memory formation Thalamus, consciousness and sleep
Limbic system, memory formation
Damaged cellular organelles are transported to ____, which perform autophagy: Peroxisome Golgi Endoplasmic reticulum Lysosome
Lysosome (lysosomes do old organelles, peroxisomes do toxins)
Which of the following is an example that employs negative feedback mechanisms? An event of blood clotting Uterine contractions leading to childbirth Opening of voltage-gated sodium channels leading to an action potential Maintenance of body temperature
Maintenance of body temperature
Which region of the brain is responsible for controlling autonomic functions (e.g. respiration, cardiac, swallowing)? Medulla oblongata Cortex Hippocampus Limbic system Amygdala
Medulla oblongata
With facilitated diffusion and carrier-mediated transport across the plasmalemma, Carrier proteins are not very selective Similar molecules do not compete for carrier proteins There is a maximum rate of transport Saturation of carriers results in a cessation/stoppage of transport A loss of carriers will not decrease the rate of transport if the concentration of the substance is low
There is a maximum rate of transport
If a hormone caused a change in cell function with a corresponding increase in the amount of messenger RNA within the cell, one would expect the action of the hormone to first turn on the process of: Replication Nuclear proliferation Transcription Translation
Transcription (= dna to mrna with messenger in nucleus)
The process of _____ occurs in the _____, and the _____ occurs in the ______ Transcription, nucleus, translation, endoplasmic reticulum Translation, cytosol, replication, Golgi Replication, nucleus, transcription, cytosol Transcription, nucleus, translation, cytosol
Transcription (dna to mrna), nucleus, translation, cytosol (replication, DNA, nucleus)
The active transport of glucose across the cell membrane: Requires endocytosis Uses the sodium concentration gradient Is an example of facilitated diffusion Is an enzyme that can hydrolyze ATP
Uses the sodium concentration gradient
The process of osmosis is a movement of _____ through a semi-permeable membrane from ______ to _____ osmolarity solutions Water - high - low Water - low - high Solute - high - low Solute - low - high
Water - high - low
The cytosol includes: All of the following Mitochondria Nucleus Endoplasmic reticulum Water and electrolytes
Water and electrolytes
15. An increase in the neuronal membrane permeability to potassium would be expected to result in: A. depolarization B. hyperpolarization C. repolarization D. no change in resting membrane potential
hyperpolarization
Which of the following substances are found routinely in the cytoplasm of eukaryotes? Chromatin DNA Nucleoli mRNA
mRNA
13. The neurotransmitter released by the preganglionic sympathetic neuron usually binds to a: A. nicotinic cholinergic receptor B. muscarinic cholinergic receptor C. metabotropic receptor D. beta adrenergic receptor E. alpha adrenergic receptor
nicotinic cholinergic receptors
