Shared Flashcard Set

Details

SP 4A-RG: Neurons and Membrane Transport
SP 4A-RG: Neurons and Membrane Transport Notecards
257
Physiology
Undergraduate 3
10/06/2012
Click here to study/print these flashcards.

Create your own flash cards! Sign up here.

Additional Physiology Flashcards

 

 

Cards

Term
The __________ is the structural and functional unit of the nervous system.
 Definition
1) Neuron
Term
The __________ __________ is the metabolic engine for axons.
 Definition
1) Cell body
Term
The __________ are branching extensions of the soma of the neuron and serve as the major area of synaptic input.
 Definition
1) Dendrites
Term
What is another name for the cell body of an axon?
 Definition
1) Soma
Term
What is the function of the cell body in a neuron?
 Definition
1) Serves as the metabolic engine for axons
Term
What is the function of dendrites in a neuron?
 Definition
1) Branching extensions of the soma where synaptic input occurs
Term
Where is the major area of synaptic input in an axon?
 Definition
1) Within a dendrite
Term
True or False: The diameter and length of an axon varies with neuron type.
 Definition
1) TRUE
Term
About how many neurons can be found within the nervous system?
 Definition
1) 10^12
Term
__________ are supportive cells which metabolically and physically support the neuron in addition to isolate individual neurons and help maintain internal milieu
 Definition
1) Neuroglia
Term
About how many neuroglia are found within the nervous system?
 Definition
1) 10^13
Term
What is the average number of neurons found in the brain?
 Definition
1) 100 billion
Term
What is the average number of synapses for a "typical" neuron?
 Definition
1) 1,000 - 10,000
Term
__________ __________ __________ are proteins which reversibly bind oxygen.
 Definition
1) Oxygen binding proteins
Term
__________ is a member of the vertebrate globin family involved in cellular oxygen homeostasis.
 Definition
1) Neuroglobin
Term
The brain uses __________ of total resting oxygen and __________ of glucose consumed in the body.
 Definition
1) 20%
2) 50%
Term
The brain is __________ of all body weight and receives __________-__________ of blood pumped out by the heart.
 Definition
1) 2%
2) 15%-20%
Term
Brain damage occurs when there is oxygen deprivation for __________-__________ minutes or if the brain's glucose supply is cut off for longer than __________-__________ minutes.
 Definition
1) 4-5
2) 10-15
Term
How does brain damage occur?
 Definition
1) When oxygen is deprived from the brain for 4-5 minutes
2) When the brain's glucose supply is cut off for longer than 10-15 minutes
Term
A __________ occurs when blood flow is interrupted to part of the brain.
 Definition
1) Stroke
Term
What is a stroke? Why does it occur? What are the negative consequences associated with a stroke?
 Definition
1) A stroke occurs when blood flow is interrupted to part of the brain
2) Blood is needed within the brain to supply oxygen and remove waste products; without a constant supply of blood to the brain, brain cells quickly began to die
3) Depending on the part of the brain affected, a stroke may cause paralysis, speech impairment, memory loss, coma, or even death
Term
A typical neuron consists of __________, a __________ __________, and an __________ with a terminal ending.
__________ receive input, have a large surface area, and have electrical signals which are graded and sent to the __________ __________.
The __________ contains a nucleus, stacks of ER, a Golgi complex, mitochondria, etc.
 Definition
1) Dendrites
2) Cell body (soma)
3) Axon
4) Dendrites
5) Cell body
6) Soma
Term
Which portion of the neuron has a terminal ending?
 Definition
1) Axon
Term
Which portion of the neuron sends electrical signals to the cell body?
 Definition
1) Dendrites
Term
Which portion of the neuron receives electrical signals from the dendrites?
 Definition
1) The cell body
Term
Which portion of the neuron integrates graded potentials from dendrites?
 Definition
1) The cell body
Term
What are the three types of structural neurons? Of functional neurons?
 Definition
1A) Multipolar
1B) Bipolar
1C) Unipolar
2A) Sensory /afferent
2B) Motor / efferent
2C) Interneurons
Term
__________ __________ inform the CNS about conditions in both the external and internal environment.
 Definition
1) Afferent neurons
Term
What is the role of afferent neurons?
 Definition
1) Inform the CNS about conditions in both the external and internal environment
Term
__________ __________ carry instructions from the CNS to effector organs (such as muscles and glands).
 Definition
1) Efferent neurons
Term
What is the function of efferent neurons?
 Definition
1) Carry instructions from CNS to effector organs (such as muscles and glands)
Term
__________ are found entirely within the CNS.
 Definition
1) Interneurons
Term
Where are interneurons located?
 Definition
1) Only within the CNS
Term
What are interneurons responsible for?
 Definition
1) Integrating afferent information and formulating an efferent response
2) Higher mental functions associated with the mind
Term
Sensory information is first obtained by a __________ __________. The information obtained by the receptor is passed down an __________ __________ through the PNS to the __________ __________ (soma) of the neuron which ends in axon terminals. These terminals are connected to an intermediary known as the __________ (which are ONLY found within the __________) which connects both neurons (__________ and __________) and passes the information along to the next neuron, the __________ __________. Here, the information is further passed down the neuron until it reaches the __________ __________at the end of the neuron where the information is finally passed to __________ __________ (muscles or glands).
 Definition
1) Sensory receptor
2) Afferent neuron
3) Cell body
4) Interneuron
5) CNS
6) Afferent
7) Efferent
8) Efferent neuron
9) Axon terminals
10) Effector organs
Term
In mammals, __________ __________ transport is 100-400 mm/day.
 Definition
1) Fast axonal
Term
What is the rate for fast axonal transport in mammals?
 Definition
1) 100-400 mm/day
Term
In mammals, __________ __________ is 1-5 mm/day.
 Definition
1) 1-5 mm/day
Term
What is the rate for slow axonal transport in mammals?
 Definition
1) 1-5 mm/day
Term
__________ help to guide axonal transport.
 Definition
1) Microtubules
Term
What motor proteins are involved in axonal transport?
 Definition
1) Kinesin
2) Dynein
Term
__________ __________ has been proposed to depend on the movement of transport filaments. Energy is required and is supplied by __________. __________ control the level of cations in the axoplasm by supplying ATP to the ion pumps. An important cation for axonal transport is __________. Transport filaments move along the __________ by means of __________-__________.
 Definition
1) Axonal transport
2) Glucose
3) Mitochondria
4) Ca+
5) Cytoskeleton
6) Cross-bridges
Term
During the retrograde phase of __________ __________, __________ recycle vesicles to the soma.
 Definition
1) Axonal transport
2) Dynein
Term
During the anterograde of __________ __________, __________ replenishment of synaptic vesicles and enzymes for the synthesis of neurotransmitters takes place.
 Definition
1) Axonal transport
2) Kinesin
Term
What are the steps that occur for axonal transport of membranous organelles?
 Definition
1) Peptides are synthesized and packaged
2) Fast axonal transport along the microtubule network
3) Vesicles contents are released by exocytosis
4) Synaptic vesicle recycling
5) Retrograde fast axonal transport
6) Old membrane components digested in lysosomes
Term
__________ __________ utilize fast transport from the soma of the __________ __________ to the __________ junction.
 Definition
1) Synaptic vesicles
2) Motor neuron
3) Neuromuscular
Term
__________ __________ __________ carries enzymes that are not used quickly and utilizes __________ flow.
 Definition
1) Slow axonal transport
2) Axoplasmic
Term
__________ __________ __________ utilizes kinesins, dyneins and microtubules to actively walk vesicles up or down axon along the __________.
 Definition
1) Fast axonal transport
2) Microtubule
Term
__________ are also called glial cells.
 Definition
1) Neuroglia
Term
Unlike neurons, glial cells do NOT initiate or conduct __________ __________.
 Definition
1) Nerve impulses
Term
True or False: Neuroglia communicate with neurons and among themselves via electrical signals
 Definition
1) FALSE: Neuroglia communicate with neurons and among themselves via CHEMICAL signals
Term
__________ serve as the connective tissue of the CNS.
 Definition
1) Neuroglia
Term
What is the primary function of the neuroglia?
 Definition
1) Serve as the connective tissue of the CNS by physically, metabolically, and functionally supporting interneurons
Term
What are the six major types of neuroglia (CNS and PNS)?
 Definition
CNS:
1) Astrocytes
2) Oligodendrocytes
3) Microglia
4) Ependymal cells
PNS:
5) Schwann cells
6) Satellite cels
Term
What type of neuroglia are named for their starlike shape?
 Definition
1) Astrocytes
Term
Which neuroglia are the most abundant?
 Definition
1) Astrocytes
Term
Which neuroglia serve as the main "glue" of the CNS by holding neurons together?
 Definition
1) Astrocytes
Term
Which neuroglia guide neurons during fetal brain development?
 Definition
1) Astrocytes
Term
Which neuroglia induce capillaries of the brain to undergo changes that aid in the establishment of a blood-brain barrier?
 Definition
1) Astrocytes
Term
Which neuroglia play an important role in the repair of brain injuries and in neural scar formation?
 Definition
1) Astrocytes
Term
Which neuroglia play a role in neurotransmitter activity?
 Definition
1) Astrocytes
Term
Which neuroglia take up and degrade glutamate and GABA (neurotransmitters)?
 Definition
1) Astrocytes
Term
Which neuroglia take up excess K+ from brain ECF?
 Definition
1) Astrocytes
Term
Why is it important for neuroglia to take up excess K+ from brain ECF? What would occur if this didn't happen?
 Definition
1) Helps maintain optimal ion conditions for neural excitability
2) The brain wouldn't work at optimal capacity
Term
Which neuroglia (along with other glial cells) enhance synapse formation and modify synaptic transmission?
 Definition
1) Astrocytes
Term
Which neuroglia form myelin sheaths around axons in the CNS?
 Definition
1) Oligodendrocytes
Term
Which neuroglia serve as the immune defense cells of the CNS?
 Definition
1) Microglia
Term
Which neuroglia in resting states release low levels of growth factors which help neurons and other glial cells survive and thrive?
 Definition
1) Microglia
Term
__________ __________ __________ helps neurons and glial cells survive.
 Definition
1) Nerve growth factor
Term
What is nerve growth factor? Which neuroglia are responsible for secreting it?
 Definition
1) Growth factor which helps neurons and glial cells survive
2) Microglia
Term
Which neuroglia line internal, fluid-filled cavities of the CNS?
 Definition
1) Ependymal cells
Term
Which neuroglia in ventricles of the brain help form and circulate cerebrospinal fluid?
 Definition
1) Ependymal cells
Term
Which neuroglia are the most abundant?
 Definition
1) Astrocytes
Term
Which neuroglia nurture and support cells and buffer ions?
 Definition
1) Astrocytes
Term
Which neuroglia have lots of branches to grab vessels to bring in nutrients?
 Definition
1) Astrocytes
Term
Which neuroglia are phagocytes and serve as the main defense cells of the CNS?
 Definition
1) Microglial cells
Term
Which neuroglia line cavities of the CNS?
 Definition
1) Ependymal cells
Term
Which neuroglia have cilia to help move cerebral spinal fluid around?
 Definition
1) Ependymal cells
Term
Which neuroglia form the myelin sheaths of the CNS?
 Definition
1) Oligodendrocytes
Term
Which neuroglia form the myelin sheath of the PNS (one per neuron)?
 Definition
1) Schwann cells
Term
Which neuroglia are in the ganglia and are like astrocytes in that they are positioned around the cell body?
 Definition
1) Satellite cells
Term
Which neuroglia form barriers between compartments?
 Definition
1) Ependymal cells
Term
Which neuroglia act as scavengers?
 Definition
1) Microglia
Term
Which neuroglia take up K+ neurotransmitters?
 Definition
1) Astrocytes
Term
Which neuroglia secrete neurotrophic factors (CNS)?
 Definition
1) Astrocytes
Term
Which neuroglia help form the blood brain barrier?
 Definition
1) Astrocytes
Term
Which neuroglia provide support for the CNS?
 Definition
1) Astrocytes
Term
Which neuroglia form myelin sheaths?
 Definition
1) Schwann cells (PNS)
2) Oligodendrocytes (myelin sheaths)
Term
Which neuroglia secrete neurotrophic factors (PNS)?
 Definition
1) Schwann cells
Term
Which neuroglia form neural scar tissue?
 Definition
1) Astrocytes
Term
Which neuroglia take up and degrade neurotransmitters?
 Definition
1) Astrocytes
Term
Which neuroglia release nerve growth factors?
 Definition
1) Microglia
Term
Which neuroglia serve as neural stem cells with the potential to form new neurons and glial cells?
 Definition
1) Ependymal cells
Term
What is the skin responsible for?
 Definition
1) Emission of heat, water, and salt
Term
What is the kidney responsible for?
 Definition
1) Regulation of water, salt, and acid levels
Term
What are the lungs responsible for?
 Definition
1) Exchange of gases
Term
What is the digestive tract for?
 Definition
1) Uptake of nutrients, water, and salts
2) Excretion of solid waste and toxins
Term
What is the kidney for?
 Definition
1) Excretion of excess water, salts, and acids: excretion of waste and toxins
Term
What are muscle and bones for?
 Definition
1) Movement, support, and protection
Term
What is the brain for?
 Definition
1) Reception and processing of signals; regulation
Term
The average urine output for adults is about __________ liters a day.
You lose close to an an additional liter of water a day through __________, __________, and __________ __________.
Food usually accounts for __________ of your total fluid intake, so if you consume __________ of water or other beverages a day along with your normal diet, you will typically replace the lost fluids.
The best rule to follow is the __________ 8-ounce glasses of water a day.
 Definition
1) 1.5
2) Breathing, sweating, and bowel movements
3) 20%
4) Two liters
5) Eight
Term
Men should consume roughly __________ liters of total beverages a day, while women should consume __________ liters.
 Definition
1) 3
2) 2.2
Term
The primary ECF cation is __________ and the primary ICF cation is __________.
The difference is maintained by basolateral __________ /__________ ATPases (transport __________ __________ out of the cell in exchange for __________ __________ molecules into the cell)
 Definition
1) Sodium
2) Potassium
3) Na+ / K+
4) Three Na+
5) Two K+
Term
What is the primary cation for ECF? for ICF?
 Definition
1) Na+
2) K+
Term
How many Na+ are transferred out of the for how many K+?
 Definition
1) Three Na+
2) Two K+
Term
The plasma membrane is composed of a __________ __________ embedded with __________. __________ proteins extend through the thickness of the membrane or are partially submerged in the membrane, and __________ proteins are loosely attached to the surface of the membrane. Short __________ chains attach to proteins or lipids on the __________ surface only.
 Definition
1) Lipid bilayer
2) Proteins
3) Integral
4) Peripheral
5) Carbohydrate
6) Outer
Term
In the lipid bilayer, which proteins extend through the thickness of the membrane? Which are loosely attached to the surface of the membrane?
 Definition
1) Integral
2) Peripheral
Term
The __________ __________ is an extremely thin layer of lipids and protein that forms the outer boundary of every cell.
 Definition
1) Plasma membrane
Term
What is the plasma membrane?
 Definition
1) Extremely thin layer of lipids and proteins that forms the outer boundary of every cell
Term
What is the role of the plasma membrane?
 Definition
1) Controls movement of molecules between the cell and its environment
2) Participates in joining cells to form tissues and organs
3) Plays an important role in the ability of a cell to respond to changes in the cell's environment
Term
The heads of the phospholipid bilayer are __________ charged, and are __________ and __________.
The tails of the phospholipid bilayer are __________, __________ and __________.
 Definition
1) Negatively
2) Polar
3) Hydrophilic
4) Uncharged
5) Nonpolar
6) Hydrophobic
Term
__________ are attached to or inserted within the __________ __________ of the plasma membrane.
 Definition
1) Proteins
2) Lipid bilayer
Term
What are the roles of the proteins within the plasma membrane?
 Definition
1) Span membrane to form water-filled pathways or channels across the lipid bilayer
2) Serve as carrier molecules
3) Serve as docking-marker acceptors
4) Membrane-bound enzymes
5) Receptor sites
6) Call adhesion molecules (CAMs)
7) Proteins on surface are important in cell's ability to recognize "self" and in cell-to-cell interaction
Term
What are the functions of the lipid bilayer of the plasma membrane?
 Definition
1) Forms basic structure of the membrane
2) Hydrophobic interior serves as barrier to passage of water soluble substances between ICF and ECF
3) Responsible for fluidity of the membrane
Term
Distribution of solutes in the body depends on what two factors?
 Definition
1) Selective permeability of the cell membrane
2) Transport mechanisms available
Term
All I need is 116, to brag on my Lord, Romans 1:16, we walking with Him daily cause He runs this thing, can I do it? Can I do it?
 Definition
Romans 1:16 - For I am not ashamed of the Gospel, as it holds the power of salvation for everyone - first the Jew, then the Gentile
Term
In the body, water is in __________ equilibrium (free movement across membranes).
Ions and most solutes are in __________ equilibrium.
 Definition
1) Osmotic
2) Chemical
Term
The __________ __________ fills the ventricles of the brain, spinal canal, and the subarachnoid space (in humans, this is a total volume of __________ mililiters.)
 Definition
1) Cerebrospinal fluid
Term
What areas of the body are filled with cerebrospinal fluid?
 Definition
1) Ventricles of the brain
2) Spinal canal
3) Subarachnoid space
Term
In humans, the choroid plexus weighs about __________ so the rate of CSF secretion is approximately __________ ml / min per __________ of tissue
 Definition
1) 2.0 grams
2) 0.2 ml / min
3) 1.0 gram
Term
The __________ __________ is selectively permeable.
 Definition
1) Cell membrane
Term
What two properties of a particle influence whether they can permeate the cell membrane without assistance?
 Definition
1) Relative solubility of the particle in a lipid
2) Size of the particle
Term
What are the types of unassisted membrane transport? Of assisted membrane transport?
 Definition
Unassisted:
1A) Diffusion
1B) Osmosis
Assisted:
2A) Carrier-mediated transport
2B) Facilitated transport
2C) Active transport
Term
In __________, there is a uniform spreading out of molecules due to their random intermingling.
 Definition
1) Diffusion (simple passive)
Term
In what type of membrane transport do molecules move from an area of higher concentration to an area of lower concentration
 Definition
1) Diffusion (simple passive)
Term
What are the important roles of simple passive diffusion?
 Definition
1) Facilitates exchange of oxygen and carbon dioxide between blood and air in lungs
2) Moves substances across kidney tubules
Term
What occurs if a substance can permeate the membrane?
 Definition
1) Diffusion can occur
Term
What occurs if the membrane is impermeable to a substance?
 Definition
1) No diffusion occurs
Term
How does the concentration gradient of a substance effect the net rate of diffusion across a membrane?
 Definition
1) Increases the rate
Term
How does the surface area of a membrane effect the net rate of diffusion across a membrane?
 Definition
1) Increases the rate
Term
How does liquid solubility effect the net rate of diffusion across a membrane?
 Definition
1) Increases the rate
Term
How does molecular weight of a substance effect the net rate of diffusion across a membrane?
 Definition
1) Decreases the rate
Term
How does distance (thickness) effect the net rate of diffusion across a membrane?
 Definition
1) Decreases the rate
Term
__________ is the diffusion of water.
 Definition
1) Osmosis
Term
In __________, water moves through a semi-permeable membrane from a region of __________ solute concentration to a region of __________ solute concentration.
 Definition
1) Osmosis
2) Lower
3) Higher
Term
What is osmosis?
 Definition
1) The diffusion of water through a semi-permeable membrane from a region of lower solute concentration to a higher solute concentration
Term
A solution with high solute concentration is __________ or __________.
 Definition
1) Hypertonic
2) Hyperosmotic
Term
What does it mean for a solution to be hypertonic (hyperosmotic)?
 Definition
1) The solution has a high solute concentration
Term
A solution with lower solute concentration is __________ or __________.
 Definition
1) Hypotonic
2) Hypoosmotic
Term
What does it mean for a solution to be hypotonic (hypoosmotic)?
 Definition
1) The solution has a low solute concentration
Term
How does the cell recover from a hypotonic shock?
 Definition
1) By ridding itself of K+ and Cl-
Term
How does the cell recover from a hypertonic shock?
 Definition
1) By ridding itself of Na+ and Cl-
Term
When internal cellular solute concentration is equal to the external solute concentration, the internal and external fluids are __________ or __________.
 Definition
1) Isotonic
2) Isosmotic
Term
What does it mean for a solution to be isotonic (isosmotic)?
 Definition
1) The internal cellular solute concentration is equal to the external solute concentration
Term
The choroid plexus demonstrates the highest expression of __________ of any human tissue.
 Definition
1) AQP1
Term
__________ is likely to have a major role in mediating water transport across the apical membrane during CSF secretion
 Definition
1) AQP1
Term
__________ is widely expressed in the brain.
 Definition
1) AQP4
Term
What is responsible for the opposition of water movement across the plasma membrane?
 Definition
1) Osmotic pressure
Term
Water move freely in the body until what occurs?
 Definition
1) Osmotic equilibrium is reached
Term
__________ is the net diffusion of water down its own concentration gradient (from a region of __________ solute to __________ solute).
 Definition
1) Osmosis
2) Lower
3) Higher
Term
__________ is the movement of water across cell membranes.
 Definition
1) Osmosis
Term
__________ __________ is determined by the number of molecules in that solution. It is not dependable on factors as size of the molecules, mass, and chemical nature
 Definition
1) Osmotic pressure
Term
How is osmotic pressure determined?
 Definition
1) By the number of molecules in that solution
Term
True or False: Osmotic pressure is dependable on factors such as size of the molecules, mass, and chemical nature.
 Definition
1) FALSE: Osmotic pressure is NOT dependable on factors such as size of the molecules, mass, and chemical nature
Term
__________ __________ is the amount of pressure required to stop the process of osmosis in a system.
 Definition
1) Osmotic pressure
Term
What is osmotic pressure?
 Definition
1) The amount of pressure required to stop the process of osmosis in a system
Term
Osmotic pressure is calculated by __________ __________ law and is measured in __________.
What is the law?
What do each of the variables represent?
 Definition
1) Van Hoff's Law
2) Atmospheres (atm)
3) The law is pi = nCRT, where:
pi = Osmotic pressure (torr)
n = Number of dissociable particles per molecules
C = Total solute concentration (molar)
R = Universal gas constant (L*atm*mol*K)
T = Temperature in degrees Kelvin 298K
Term
The __________ __________ of solutes administered clinically is generally compared to the osmotic concentration of __________.
Depends on the __________ molecular weight of the solute and its __________.
 Definition
1) Osmotic concentration
2) Plasma
3) Gram
4) Dissociability
Term
The osmotic concentration of solutions administered clinically is compared to what other osmotic concentration (as a standard)?
 Definition
1) Plasma
Term
__________ __________ are those solutions having the same osmotic concentration as __________.
Consequently, administration won't alter intracellular volume.
Usually consists of solutions containing __________ mOsm of non-penetrating solute.
 Definition
1) Isotonic solutions
2) Plasma
3) 300
Term
How does the osmotic concentration of isotonic solutions compare to that of plasma? How does administration affect the intracellular volume? How much non-penetrating solute is usually found within isotonic solutions?
 Definition
1) Isotonic solutions have the same osmotic concentration as plasma
2) Administration won't alter the intracellular volume
3) Solutions contain 300 mOsm of non-penetrating solute
Term
__________ __________ are those solutions having a lesser osmotic concentration than __________.
Consequently, administration will tend to __________ intracellular volume.
Solutions contain __________ than 300 mOsm of non-penetrating solute
 Definition
1) Hypotonic solutions
2) Plasma
3) Expand
4) Less
Term
How does the osmotic concentration of hypotonic solutions compare to that of plasma? How does administration affect the intracellular volume? How much non-penetrating solute is usually found within hypotonic solutions?
 Definition
1) Hypotonic solutions have a lower osmotic concentration than plasma
2) Administration will tend to expand intracellular volume
3) Solutions contain less than 300 mOsm of non-penetrating solute.
Term
__________ __________ are those solutions having a higher osmotic concentration than __________.
Consequently, administration will tend to __________ intracellular volume.
Solutions contain __________ than 300 mOsm of non-penetrating solute.
 Definition
1) Hypertonic solutions
2) Plasma
3) Contract
4) More
Term
How does the osmotic concentration of hypertonic solutions compare to that of plasma? How does administration affect the intracellular volume? How much non-penetrating solute is usually found within hypertonic solutions?
 Definition
1) Hypertonic solutions have a higher osmotic concentration than plasma
2) Administration will tend to contract intracellular volume
3) Solutions contain more than 300 mOsm of non-penetrating solute
Term
Which membrane transport is accomplished by the membrane carrier flipping its shape?
 Definition
1) Carrier-mediated transport
Term
True or False: Carrier-mediate transport can be active or passive?
 Definition
1) TRUE
Term
What are the characteristics that determine the kind and amount of material that can be transferred across the membrane?
 Definition
1) Specificity
2) Saturation
3) Competition
Term
What are the three types of assisted membrane transport?
 Definition
1) Facilitated diffusion
2) Active transport
3) Vesicular transport
Term
Current therapeutic drugs act on what four main types of molecular targets? What percentage of these are proteins?
 Definition
1) Enzymes
2) Receptors
3) Ion channels
4) Transporters
5) 60%-70%
Term
In __________ __________ substances move from a higher concentration to a lower concentration.
 Definition
1) Facilitated diffusion
Term
True or False: Facilitated diffusion does not require a carrier molecule
 Definition
1) FALSE: Facilitated diffusion REQUIRES a carrier molecule
Term
What are one of the primary functions of facilitated diffusion?
 Definition
1) Transport glucose to cells
Term
What are the steps of facilitated diffusion?
 Definition
1) Carrier protein takes conformation in which solute binding site is exposed to region of higher concentration
2) Solute molecule binds to carrier protein
3) Carrier protein changes conformation so that the binding site is exposed to the region of lower concentration
4) Transported solute is released and carrier protein returns to conformation in step one
Term
__________ __________ moves a substance against its concentration gradient.
 Definition
1) Active transport
Term
What is active transport?
 Definition
1) When a substance is moved against its concentration gradient
Term
Does active transport require a carrier molecule?
 Definition
1) Yes
Term
What are the two types of active transport?
 Definition
1) Primary active transport
2) Secondary active transport
Term
What is the fuel used for primary active transport? For secondary active transport?
 Definition
1) Requires direct use of ATP
2) Driven by an ion concentration gradient established by a primary active transport system
Term
The energy of __________ is required in the __________-__________ cycle of the carrier to transport the molecule uphill from a region of __________ concentration to a region of __________ concentration.
 Definition
1) ATP
2) Phosphorylation-dephosphorylation
3) Low
4) High
Term
What are the steps of active transport?
 Definition
1) Carrier protein splits ATP into ADP plus phosphate. Phosphate group binds to center, increasing affinity of its binding site for ion
2) Ion to be transported binds to carrier on low-concentration side
3) In response to ion binding, carrier changes conformation so that binding sites are exposed to opposite sides of the membrane. The change in shape also reduces affinity of site for ion.
4) Carrier releases ion to side of higher concentration; phosphate group is also released
5) When binding site is free, carrier reverts to its original shape.
Term
What are the steps of membrane transport via a Na+ and K+ pump?
 Definition
1) Pump has three high affinity sites for Na+ and two lot affinity sites for K+ when exposed to ICF
2) When three Na+ from ICF (where Na+ concentration is low) bind to pump, it splits ATP into ADP plus phosphate; phosphate group binds to pump
3) Phosphorylation causes pump to change conformation so that Na+ binding sites are exposed to opposite side of membrane and three Na+ are released to ECG (where Na+ concentration is high) as affinity of Na+ binding sites greatly decreases.
4) Change in shape also exposes pump's binding sites for K+ to ECF and greatly increases affinity of K+ sites
5) When two K+ from ECF (where K+ concentration is low) bind to pump, it releases phosphate group. Dephosphorylation causes pump to revert to its original conformation
6) Two K+ are released to ICF (where K+ concentration is high) as affinity of K+ binding sites markedly decreases during change in shape. At the same time, affinity of Na+ binding sites greatly increases returning process to step one
Term
The (Na+, K+)-ATPase in the plasma membranes of most __________ cells is an __________ __________ __________. It catalyzes ATP-dependent transport of __________ out of a cell in exchange for __________ entering the cell.
 Definition
1) Animal
2) Antiport ion pump
3) Na+
4) K+
Term
In a secondary active transport symport, driving ions in __________ concentration and transported solutes in __________ concentration are brought to a region where driving ions are in __________ concentration and transported solutes are in __________ concentration.
 Definition
1) High
2) Low
3) Low
4) High
Term
In a secondary active transport antiport, driving ions in __________ concentration and transported solutes in __________ concentration are brought to a region where driving ions are in __________ concentration and transported solutes are in __________ concentration.
 Definition
1) High
2) High
3) Low
4) Low
Term
In the primary active transport of Na+ and K+, for every __________ Na+ __________ K+ are traded via ATP.
__________ is also transported through a uniporter.
 Definition
1) Three
2) Two
3) Glucose
Term
In the secondary active transport of Ca+, __________ Na+ are traded for every __________ Ca+ through an __________.
 Definition
1) Three
2) One
3) Antiporter
Term
__________ __________ is the movement of particles from an area of lower concentration to an area of higher concentration against the concentration gradient.
 Definition
1) Active transport
Term
What is active transport?
 Definition
1) The movement of particles from an area of lower concentration to an area of higher concentration against the concentration gradient
Term
How is active transport powered? What is used to transport the solutes? What are the outcomes from all of these processes?
 Definition
1) ATP
2) Na+ / K+ pump
3) Gradients and polarity are created
Term
In __________ __________, material is moved into our out of the cell wrapped in membrane
 Definition
1) Vesticular transport
Term
Is vesticular transport an active or passive form of membrane transport?
 Definition
1) Active
Term
What are the two types of vesticular transport?
 Definition
1) Endocytosis
2) Exocytosis
Term
__________ is the process by which substances move into the cell.
 Definition
1) Endocytosis
Term
__________ is a nonselective uptake of ECF while __________ is a selective uptake of multimolecular particles.
 Definition
1) Pinocytosis
2) Phagocytosis
Term
What is pinocytosis?
 Definition
1) Nonselective uptake of ECF
Term
What is phagocytosis?
 Definition
1) Selective uptake of multimolecular particles
Term
__________ provides the mechanisms for secreting large polar molecules.
 Definition
1) Exocytosis
Term
What is exocytosis? What are the outcomes of the process?
 Definition
1) Exocytosis is a mechanism for secreting large polar molecules
2) The process enables cells to add specific components to the plasma membrane
Term
__________ is the reverse of exocytosis and allows macromolecules to enter the cells.
 Definition
1) Endocytosis
Term
In __________, a substance is progressively enclosed by an enfolding portion of the __________ __________.
This forms a __________ which will pinch off of the plasma membrane and enter the __________ where it is typically digested.
 Definition
1) Endocytosis
2) Plasma membrane
3) Vesicle
4) Cytosol
Term
What are the three types of endocytosis?
 Definition
1) Phagocytosis
2) Pinocytosis
3) Receptor-mediated endocytosis
Term
What is the main mechanism for the specific uptake of macromolecules by most cells?
 Definition
1) Endocytosis
Term
What form of endocytosis is only performed by macrophages and white blood cells?
 Definition
1) Phagocytosis
Term
What form of endocytosis is non-selective?
 Definition
1) Pinocytosis
Term
Phagocytosis is typically only performed by what cells?
 Definition
1) Macrophages
2) White blood cells
Term
What molecules are taken up by the cells via receptor-mediated endocytosis (RME)?
 Definition
1) Enzymes
2) Hormones
3) Low-density lipoproteins (LDL)
3) Flu viruses and the diphtheria toxin which use RME to enter cells
Term
What process literally means "out of the cell"?
 Definition
1) Exocytosis
Term
What process accounts for hormone secretion, neurotransmitter release, mucus secretion, and ejection of wastes?
 Definition
1) Exocytosis
Term
What is exocytosis responsible for?
 Definition
1) Hormone secretion
2) Neurotransmitter release
3) Mucus secretion
4) Ejection of wastes
Term
What are the steps for the process of exocytosis?
 Definition
1) Inside the cell, the substance to be exported is enclosed in a membranous sac called a vesicle
2) The vesicle will migrate to the PM, fuse with it, and then rupture, spilling the contents into the extracellular space
Term
What process literally means "cell-eating"?
 Definition
1) Phagocytosis
Term
What are the cytoplasmic extensions used by phagocytes called?
 Definition
1) Pseudopods
Term
What are the steps for the process of phagocytosis?
 Definition
1) Cytoplasmic extensions called pseudopods "reach out and grab" large, solid, material such as a clump of bacteria or cell debris, and then engulf it
2) The resulting vesicle is called a phagosome; it fuses with a lysosome (organelle that contains digestive enzymes) and the contents of the phagosome are ingested
Term
What process literally means "cell-drinking"?
 Definition
1) Pinocytosis
Term
What are the steps for the process of pinocytosis?
 Definition
1) A bit of infolding plasma membrane surrounds a droplet of extracellular fluid containing dissolved molecules; this creates a tiny membranous vesicle
Term
True or False: Most cells routinely perform pinocytosis.
 Definition
1) TRUE
Term
What is the difference between phagocytosis and pinocytosis?
 Definition
1) Pinocytosis is unselective, while phagocytosis often uptakes macromolecules
Term
The composition of intracellular and extracellular fluid is tightly controlled by regulated __________ __________.
 Definition
1) Transport mechanisms
Term
Concentration of most __________ and __________ substances is different in intracellular and extracellular fluids.
 Definition
1) Ions
2) Organic substances
Term
Homeostasis and life depends on the regulation of __________.
 Definition
1) Transport
Term
Most solutes are concentrated in either one compartment or the other, creating a state of __________ __________.
 Definition
1) Chemical disequilibrium
Term
Cations and anions are not distributed equally between the body compartments, creating a state of __________ __________.
 Definition
1) Electrical disequilibrium
Term
Water moves freely between the cells and ECF, resulting in a state of __________ __________.
 Definition
1) Osmotic equilibrium
Term
The movement of water across a membrane in response to a concentration gradient is called __________.
 Definition
1) Osmosis
Term
To compare solution concentrations, we express the concentration in terms of __________, the number of particles (ions or intact molecules) per liter of solution, expressed as milliosmoles per liter.
 Definition
1) Osmolarity
Term
__________ of a solution describes the cell volume change that occurs at equilibrium if the cell is placed in that solution.
Cells swell in __________ solutions and shrink in __________ solutions.
If the cell does not change size at equilibrium, the solution is __________.
 Definition
1) Tonicity
2) Hypotonic
3) Hypertonic
4) Isotonic
Term
The osmolarity of a solution cannot be used to determine the tonicity of the solution.
The relative concentrations of __________ __________ in the cell and in the solution determine tonicity.
__________ __________ contribute to the osmolarity of a solution but not to its tonicity.
 Definition
1) Nonpenetrating solutes
2) Penetrating solutes
Term
In __________ __________ a pressure gradient moves a fluid along with its dissolved and suspended materials.
 Definition
1) Bulk flow
Term
The __________ __________ is a selectively permeable barrier that restricts free exchange between cell and the interstitial fluid. The movement of a substance across the membrane depends in the __________ of the membrane to the substance.
 Definition
1) Cell membrane
2) Permeability
Term
Movement of molecules across membranes can be classified either by __________ requirements or by the __________ means the molecule uses to cross the membrane.
 Definition
1) Energy
2) Physical
Term
__________-soluble substance can diffuse through the phospholipid bilayer. Less __________-soluble molecules require the assistance of a membrane to cross the membrane.
 Definition
1) Lipid
Term
__________ __________ does not require the input of energy.
 Definition
1) Passive transport
Term
__________ is the passive movement of molecules down a chemical (concentration) gradient from an area of higher to lower concentration.
Net movement ceases when the system reaches __________ although molecular movement continues.
 Definition
1) Diffusion
2) Equilibrium
Term
Diffusion rate depends on the __________ of the concentration gradient; it is __________ over long distances, is directly related to __________, and is inversely related to __________.
 Definition
1) Magnitude
2) Slow
3) Temperature
4) Size
Term
__________ __________ across a membrane is directly proportional to membrane surface area, concentration gradient, and membrane permeability, and inversely proportional to membrane thickness.
 Definition
1) Simple diffusion
Term
Most molecules cross membranes with the aid of __________ __________.
 Definition
1) Membrane proteins
Term
Membrane proteins have four functional roles: __________ __________ maintain cell shape and form cell junctions; __________-__________ enzymes catalyze chemical reactions and help transfer signals across the membrane; __________ __________ are part of the body's signaling system; and __________ __________ move many molecules into or out of the cell.
 Definition
1) Structural proteins
2) Membrane-associated enzymes
3) Receptor proteins
4) Transport proteins
Term
__________ __________ form water-filled channels that link the intracellular and extracellular compartments.
 Definition
1) Channel proteins
Term
__________ __________ regulate movement of substances through them by opening and closing. They may be regulated by __________, by the electrical state of the cell, or by physical changes such as pressure.
 Definition
1) Gated channels
2) Ligands
Term
__________ __________ never form a continuous connection between the intracellular and extracellular fluid. They bind to substrates, then change __________.
 Definition
1) Carrier proteins
2) Conformation
Term
Protein-mediated diffusion is called __________ __________ it has the same properties as simple diffusion.
 Definition
1) Faciliated diffusion
Term
__________ __________ moves molecules against their concentration gradient and requires an outside source of energy.
 Definition
1) Active transport
Term
In __________ __________ __________ (direct) the energy comes directly from ATP.
In __________ __________ __________ (indirect) uses the potential energy stored in a concentration gradient and is indirectly driven by energy from ATP.
 Definition
1) Primary active transport (direct)
2) Secondary active transport (indirect)
Term
The most important active transporter is the __________-__________-__________ which pumps Na+ put of the cell and K+ into the cell.
 Definition
1) Sodium-potassium-ATPase
Term
Most secondary active transport systems are driven by the __________ concentration gradient.
 Definition
1) Sodium
Term
All carrier-mediated transport demonstrates __________, __________, and __________.
 Definition
1) Specificity
2) Competition
3) Saturation
Term
__________ refers to the ability of a transporter to move only one molecule or a group of closely related molecules.
 Definition
1) Specificity
Term
__________ occurs when a group of membrane transports are working at their maximum rate.
 Definition
1) Saturation
Term
In __________-__________ __________ ligands bind to membrane receptors that concentrate in coated pits or caveolae.
 Definition
1) Receptor-mediated endocytosis
Term
In __________, the vesicle membrane fuses with the cell membrane before releasing its contents into the extracellular space; requires ATP.
 Definition
1) Exocytosis
Term
Although the total body is electrically neutral, diffusion and active transport of ions across the cell membrane create an __________ __________ with the inside of cells negative relative to the extracellular fluid.
 Definition
1) Electrical gradient
Term
The electrical gradient between the extracellular fluid and the intracellular fluid is known as the __________ __________ __________ __________.
 Definition
1) Resting membrane potential difference
Term
The movement of an ion across the cell membrane is influenced by the __________ __________ for that ion.
 Definition
1) Electrochemical gradient
Term
The membrane potential that exactly opposes the concentration gradient of an ion is known as the __________ __________. The equilibrium potential for any ion can be calculated using the __________ equation.
 Definition
1) Equilibrium potential
2) Nernst
Term
In most living cells, __________ is the primary ion that determines the resting membrane potential.
 Definition
1) K+
Term
The use of __________ signals to initiate a cellular response is a universal property of living cells. Pancreatic __________ cells release insulin in response to a change in membrane potential.
 Definition
1) Electrical
2) Beta
Supporting users have an ad free experience!