Exam 1- February 19th Flashcards
Phospholipid molecules make up most of the ______ bilayer.
Lipid
The lipid bilayer includes __________ and cardiac glycosides.
Cholesterol
“polar” end means that this highly charged phosphate group is considered
hydrophilic
“non-polar” end means that the two long uncharged carbon chains that form tails is considered
hydrophobic
Phospholipids are ___________, which means they are both water and lipid soluble.
amphipathic
Embedded in the lipid bilayer are membrane _______ which penetrate one or both of the lipid layers.
proteins
Model of individual proteins floating about the lipid bilayer
Singer-Nicholson fluid mosaic model
To move things into or out of the cell or vis-versa
Transport
3 things that are transported
1) Protein pores & gated channels
2) Carrier Proteins or Transporters
3) Na+/K+ ATPase Enzyme proteins
This function of cell membrane proteins is important in immunology & development
Recognition
Recognition surfaces glycoproteins as _______.
markers
Recognition also places antigen-recognition receptors on _______ cells.
immune
One function of cell membrane proteins is to surface protein receptors for hormones, nerve transmitters & other factors; physical stimuli. Which cell membrane protein does this?
Signal Reception
Attach cell to cell
protein junctions
Stick cell to surface for crawling, anchoring, and association of cells into tissues.
Adhesion proteins
Separation of charges/_____ causes a voltage to develop. Especially important in explaining actions of nerve, muscle and hair-cell membranes.
ions
These enzymes are associated with receptor or carrier proteins or alone.
Membrane-attached Enzymes
This gives the cell its shape
cytoskeleton
A ______ is made up of more than 100 ______ ______, connected by ________ _______.
Protein is made up of more than 100 amino acids, connected by peptide bonds.
Shorter chains are called
polypeptides
How many different amino acids are used in human proteins?
21
How many different amino acids can be used in plant proteins?
Up to 26
Several proteins may bind together to form a single large assembly called a
multimeric protein
In multimeric proteins, each protein component is called a
sub-unit
Membranes are ___________ permeable.
selectively
Molecules move through the membrane in different ways, depending whether they are __________ or __________.
Hydrophilic or Hydrophobic
Some molecules may move through a membrane with no added energy, this is known as passive _______ or passive _______.
Passive transport or passive diffusion
Examples of lipid-soluble solutes transported through the phospholipid layer are:
gases, fat-soluble vitamins, fats, and steroid hormones
Examples of solutes transported through pores are:
H+ ion, K+ ion, Cl- ion, urea, and water
Examples of solutes transported by carrier proteins through the membrane:
glucose, other simples sugars, amino acids and nucleic acids
This does not require added energy because it uses thermal energy already present in all molecules with a temperature.
Passive transport
Another term for passive transport is
passive diffusion
When a substance moves by lipid solubility through the phospholipid bilayer it is referred to as a
lipid-soluble solute
Gases (CO2 and 02), the fat soluble vitamins (A,D,E and K), fats, steroid hormones (estrogen, testosterone, cortisol) are all examples of what?
lipid-soluble solutes
Water filled pores are known as
channels
When a substance moves through water-filled pores it is known as a
solute
H+ ions, K+ ions, Cl- ions, urea, and water are all examples of what?
Solutes that can be transported through pores
Glucose, other simple sugars, amino acids and nucleic acids are all examples of what?
Solutes that can be transported by carrier proteins through the membrane
What does not require added energy?
Passive Transport
As a rule of passive transport, the membrane must be _______ _________ to a given substance, this way molecules can pass through the membrane coming in or going out.
Selectively permeable
As another rule of passive transport, passive transport is ____________, meaning that molecules may move in both directions.
bidirectional
One rule of passive transport states that molecules, ions, or atoms always move from _____ concentration to _____ concentration.
high to low
The movement of each species of particle by passive transport is considered _________. For further explanation, the movement of glucose, urea, Na+ ion and glycine would depend on the IN/OUT concentrations of each considered without regard to the others.
separately
The rate of passive transport or passive diffusion of a particular substance is proportional to the permeability factor and to the difference in concentrations on each side of a membrane. This equation looks like….
Rate=PX [X out - X in]
The permeability of water through a membrane is considered equal to
1
1 mole =
6.02 x10^23 molecules/atoms/particles
Water only moves by _______ ________ through membrane pores. Therefore, water only moves from HIGH [H20] to LOW [H2O].
passive transport
NaCl, CaCl2, Na2CO3 are all examples that….
ionize in water
sucrose, glucose, urea and glycerol are all examples that…
will not ionize in water, non-ionizing ions
If a solution is iso-osmotic, the cell neither _____ nor _____, but remains the same _______.
If a solution is iso-osmotic, the cell neither swells nor shrinks, but remains the same volume.
_____ moles of dissolved particles/liter, is ISO-OSMOTIC for mammalian cells (including red blood cells).
0.29
A solution is ________ if the [dissolved particles] is less than iso-osmotic.
Hypotonic
Hypotonic solutions will cause the cell to…..
swell
A solution is ________ if the [dissolved particles] is greater than iso-osmotic.
Hypertonic
Hypertonic solutions will cause the cell to…
shrink
-ase means
enzyme
(Active Transport Example)
This gland is active in iodide ion uptake
Thyroid gland
(Active Transport Example)
This intestine is active in transport of glucose and other simple sugars, amino acids and nucleic acids.
Small intestine
(Active Transport Example)
This organ has a lot of work to do, it is active in the transport of Na+ ions, Cl- ions, K+ ions, H+ ions, glucose, amino acids, Ca2+ ions, and bicarbonate ions.
Kidney
T/F: ALL CELLS exchange Na+ and K+ with Na+/K+ ATPase, these are known as chlorine-potassium pumps.
False, known as sodium-potassium pumps
Within the sodium-potassium pumps, 2 K+ IONS are transported to the _____ of the cell in exchange for 3 Na+ IONS transported to the _____ of the cell.
inside, outside
Passive transport always moves from [high] to [low], but what kind of transport can move from [low] to [high]?
Active transport can move from [low] to [high].
potential to do electrical work (measured in volts)
electrical potential
T/F: Electrical current is the movement of electrical charges (+ or - ions), as they do electrical work (measured in amperes). In cells, the electric current is carried by ions instead of electrons. The current is created when separated positive and negative charges come back together.
True
Opposite charges (ions) attract each other; like charges (ions) repel each other, this is known as the
charge rules
Protein structures in the cell membrane that allow ions or water to pass into or out of the cell
Channels or pores
protein channels through the membrane which can open and close are called Some gated channels open or close with a chemical, electrical or physical stimulus.
Gated Channels
proteins that change shape with a stimulus and open or close the channel
gates
Some gated channels open or close with certain stimuli, what are the three stimuli potentials?
Chemical, electrical or physical stimulus
Chemical Stimulus is considered
ligand-gated
Electrical stimulus is considered
voltage-gated
physical stimulus is considered
pressure-, heat-, etc-gated
separation of membrane to create an electrical potential
separation of charges
electrical potential in all cells during rest (always negative inside relative to outside)
resting potential
inside of cell become more positive relative to outside
depolarization
inside of cell becomes more negative relative to outside
hyperpolarization
the cell returns to its original resting potential
repolarization
a self-propagating, positive (depolarizing) “spike” of current through the membrane, followed by a re-setting to the resting potential (repolarization).
Action Potential
Action potentials only occur in ________ cells.
excitable
Nerve cells, Muscle cells, Fertilized ovum and secretory cells are all cells that ______ _________ can occur in.
Action potential
minimum cell potential above the resting potential to start an action potential
threshold
self-propagating in-rush of sodium ions during an action potential
“Runaway Depolariziation” or “Sodium Cycle”
used to describe the action potential, which, once started, cannot be stopped or charged in size
“All or none”
the process of resetting of membrane potential to resting potential after runaway depolarization
“Repolarization”
movement of action potentials along the cell membrane from one part of the cell to another
“Propagation of the Action Potential”
The movement of action potentials in a myelinated nerve, from one node to the next node down.
“Saltatory Propagation”
________ ___________ (in “volts”) is created in living cells by ions and can be used to create electrical current (in “amperes”)
Electrical Potential
_________ __________ create electrical potential by separating positive and negative charges. (Separation of charges)
Cell membranes
This occurs as a result of (A) an imbalance in passive transport of ions [from high to low concentrations] and (B) the rules of electric charges [likes repel;opposites attract]
Separation of charges
What are the three general types of nerves?
Motor Nerves
Sensory Nerves
Interneurons
This nerve goes from the central nervous system to muscles
Motor Nerves
This nerve goes from sensory receptors to the central nervous system
Sensory Nerves
This nerve has two processes–axons and dendtrites– and they are all over within the central nervous system
Interneurons
T/F: All cells have higher potassium ion (K+) concentrations inside and higher sodium ion (Na+), calcium ion (Ca++) and chloride ion (Cl-) concentrations outside.
True
What channel proteins are numerous and always partly open?
Potassium channel proteins
What is an example of channel proteins that are few or closed?
Na+
membrane voltage caused by separation of charges
Em
The _______ the Em, the greater potential to do electrical work.
larger
The _______ _________ is due to the movement of potassium (K+) ions, the only ion that can freely cross the membrane when the cell is at rest.
resting potential
When K+ ions leave the cell, what do they leave behind?
Immovable negative charges
balance point is called
equilibrium potential
T/F: The speed of propagation is not proportional to the diameter of nerve and whether it is myelinated or not.
False: IS PROPORTIONAL
Nerve propagation in an _____________ (naked) nerve is from patch-to-patch.
Unmyelinated
Nerve propagation down a _________ nerve is from node-to-node. Myelin speeds up propagation by about 100x compared to unmyelinated nerves.
myelinated
Myelination of nerve axons are wrappings of cell membranes from inside the central nervous system, these are called:
Oligodendrocytes
Myelination of nerve axons are wrappings of cell membranes in periphery (outside of brainstem & spinal cord), these are called
Schwann Cells
Very regular open areas that are the only exposed membrane with sodium channels that can allow Na+ ions in when stimulated.
Nodes of Ranvier
What is the most common diseases which causes demyelination of nerves and eventual paralysis?
Multiple Sclerosis (MS) and Amyotrophic lateral Sclerosis (ALS; Lou Gehrig’s Disease)
Fastest saltatory propagation is 120 meters/second (268mph), where does this occur?
In the largest, myelinated motor nerves.
connections or relay points between nerves and other nerves, between nerves and muscle, between nerves and glands and even between nerves and capillaries.
Synapses
motor nerves
nerves to muscle
motor-end-plates or myoneural junctions
motor nerves to muscle cells
Two basic types of synapses
chemical and electrical
This synapse contains a transmitter substance which has been synthesized in the presynaptic nerve cell body, packaged in membrane vesicles and transported to the nerve endings.The time involved is about 0.5 millisecond per synapse. The synapse only works in one direction.
Chemical Synapse
The time involved per synapse is known as the
synaptic delay
Nerve to nerve;
Motor nerve to muscle;
neurosecretory nerve to capillary;
ALL EXAMPLES OF WHAT SYNAPSE
Chemical synapse
Synapse common in inverts and lower vertebrates, less common in mammals
Electrical synapse
This synapse has electrical connections between cells which allow the free passage of ions through specialized protein pores through both adjacent cell membranes. This allows the cells to be electrically connected, or electrically-coupled. There is no synaptic delay and action potentials can travel both ways.
Electrical synapse
specialized protein pores are known as
gap junctions
Pore protein is made up of protein units called
connexin
CNS nerve to CNS nerve is an example of what type of synapse
Electrical synapse
In a chemical synapse, turning “off” requires either:
inactivation or re-uptake
The transmitter side of a chemical synapse is known as the
presynaptic side
The Receiver side of a chemical synapse is known as the
post=synaptic side
Excitatory transmitters are depolarizing, and they produce EPSP’s. Some examples are
- acetylcholine
- nor-epinephrine
- dopamine
- glutamic acid
Inhibitory transmitters are hyperpolarizing, and they produce IPSP’s. Some examples are
- gamma-amino butyric acid
- serotonin
EPSP
Excitatory Post-Synaptic Potential
IPSP
Inhibitory Post-Synaptic Potential
The chemical signal, ACh, is turned “off” by __________ ________ in the postsynaptic muscle membrane?
Cholinesterase enzyme
This is constructed to produce an action potential every time
Motor end plate
Two Motor End-Plate synaptic poisons:
Curare & Succinyl Choline
Muscle fibers=
muscle cells
bundle of fibers
fasciculus
Muscle cells are ________: many nuclei in one cell, representing nuclear replication without cell division.
Syncitial
Smallest unit of muscle contraction
sarcomere
Hierarchy of muscle structures:
Muscle >Fasciculus>Fiber>Myofibril
True/False: A-Band (myosin thick filaments), containing, H-Band (“hangles” of golf-club-like mysocin filaments), held together by M-Disk (grid of myosin-binding proteins to hold thick filaments in register)
True
A-BAND
myosin thick filaments
H-BAND
“handles” of golf-club-like myosin filaments
M-DISK
grid of myosin-binding proteins to hold thick filaments in register
T/F: The I-BAND, split by Z-LINE or Z-DISK.
TRUE
I-BAND
exposed actin thin filaments
Z-LINE or Z-DISK
grid of actin-binding protein - actinin – to hold thin filaments in register
In a thick filament, the head assembly is called
Heavy meromyosin
In a thick filament, the rest of the shaft is called
light meromyosin
Myosin heads can be found in two positions:
Cocked position & Fired Position
This blocks myosin heads that are ready to make contact with actin and pull
tropomyosin
Ca++ released into cytoplasm, binds to this and then it bends the tropomyosin out of the way to expose the myosin-binding site on the actin filament
troponin C
enclosed membrane system that lies entirely within muscle cell/fiber, but comes into very close contact with the cell membrane through the cell membrane’s transverse tubules.
sarcoplasmic reticulum
When an action potential travels over the muscle cell membrane, it propagates down the _________ ________ and opens the voltage-gated Ca++ channels, releasing a flood of Ca++ ions to the nearby sarcomeres, to start a contraction.
transverse tubules
A single contraction caused by a single action potential over the muslce
twitch
a sustained contraction without any relaxation caused by multiple action potentials over the muscle
tetanus
contraction force measured while muscle is not allowed to shorten
isometric
contraction force measured while muscle is under constant load, but allowed to shorten
isotonic
Maximal tetanic contractions are called
contractures or cramps
Maximum tetanic contractions caused by very rapid nerve stimulation is
> 200 AP’s/sec
time Ca++ is free in cytoplasm
duration of stimulation
membranes and connective tissue holding muscle cells together
passive eleastic elements
T/F: Glycolysis without O2 yields 2 ATP’s per molecule of sucrose used.
False, glucose used
T/F: Glycolysis along with mitochondrial Kreb’s cycle oxidation yields 22 ATP’s per molecule of glucose used.
False: 38
This holds for skeletal muscle only: “When a muscle is passively stretched, then stimulated, it contracts with greater force – within limits.”
Length-Tension Relationship
Length-Tension Relationship is similar for the cardiac muscle, this is called
Frank-Starling Law of The Heart
fusion
incomplete relaxation
summation
incomplete relaxation with greater force
tetanus
sustained contraction with no relaxation
1 motor nerve and all the muscle fibers it innervates =
1 motor unit
striated forearm muscles of fingers, stapedius muscle of middle ear, extraocular muscles of eyeball are all:
Fast skeletal muscle fibers
all major skeletal muscles are called
intermediate skeletal muscle fibers
muscles of spinal column and lower back are
slow skeletal muscle fibers
Venous sinus, atria, and the ventricles of the heart are all
cardiac muscles
Non-striated muscles such as the stomach, large & small intestine, ureters, urinary bladder, part of the esophagus, etc are all
smooth mucles
this is found in all hollow visceral organs
Visceral smooth muscle
non spontaneously contracting; cells are independent, and there are no gap junctions in this muscle
munti-unit smooth muscle
responsible for higher levels of motor control, sensory analysis, memory, associative functions, including memory:
Cortex
responsible for basic motor control
Basal Ganglia
emotional responses
limbic system; amygdala, hypothalamus
coordination of motor control with sensory input
cerebellum
vegetative functions: respiration control, blood pressure control, swallowing, vomiting.
Brainstem
sensory inputs, site of somatic motor nerve cell bodies, some reflex circuits
spinal cord
protects the central nervous system
meninges
controls skeletal muscles
somatic motor system
this supplies the motor nerves to heart and smooth muscle organs – blood vessels, bronchioles, digestive tract organs, reproductive tract organs, some glands.
Autonomic nervous system
originates in basal ganglia, its effector nerves release acetyl choline
Parasympathetic division
vagus nerve
cranial nerve
originates from the hypothalamus, its effector nerves release nor-epinephrine
sympathetic division
carry information from head and neck receptors
cranial nerves
carry information from peripheral receptors and enters them into the spinal cord through the dorsal roots
Spinal nerves
found in primates, sends motor commands from the motor cortex directly to motor nerves in the spinal cord which control the skeletal muscles
The Pyramidal Tract
leaving the CNS is referred to as
efferent
coming to the CNS is referred to as
afferent
This is the spray of spinal nerves leaving the base of the spinal cord, also known as the horse’s tail
cauda equina
________ ______ at each segment carry sensory axons into CNS; ventral roots at each segment carry myelinated motor axons out of the cord to skeletal muscles.
Dorsal roots
mostly nerve cell bodies is called
gray matter
mostly myelinated axon bundles or tracts is called
white matter
These lie completely within the cord, and carry information up and down and across the spinal cord
interneurons
The autonomic nervous systems are the nerves that control
non-skeletal muscle activity
Non-skeletal muscle activity is considered the cardiac muscle, smooth muscle organs, as well as the secretory activity of
some glands
increases rate & strength of heart contraction via cardioaccelerator nerves, raising blood pressure
SNS
decreases saliva secretion from salivary glands
SNS
causes dilation of pupil
SNS
relaxes bronchiole smooth muscle, causing bronchiole dilatation
SNS
decreases motility and secretion in digestive tract
SNS
increased perspiration from sweat glands of the skin
SNS
arterioles constrict, raising blood pressure in blood vessels
SNS
constriction of renal arterioles stops kidney filtration function
SNS
secretion of epinephrine from adrenal medulla, which mimics most effects of nor-epinephrine
SNS
contraction of spleen to release extra blood cells into circ
SNS
mediates contraction of all accessory glands and emission reflex in male; promotes uterine contractions in female
SNS
decreases rate and strength of hear contraction
PNS
increases saliva secretion from salivary glands
PNS
causes constriction of pupil
PNS
increases motility and secretion of the digestive system
PNS
mediates micturition and defecation reflexes in the urinary bladder and rectum
PNS
general stimulation of sweat glands in the skin
PNS
stimulation of tear secretion in tear glands
PNS
promotes erection in erectile tissues of males and females via pelvic splanchnic nerves releasing ACh & VIP in sex organs
PNS
