Unit 1 Flashcards
what does an unsaturated phospholipid tail mean?
it has double bonds, so it is more fluid
greater proportion of unsaturated fats means
more fluidity
phospholipids are
a. amphipathic
b. hydrophilic
c. hydrophobic
a. amphipathic
phospholipids have ______ heads and __________ tails
polar, nonpolar
is polar hydrophobic or hydrophilic
hydrophilic
why is a high surface area important in cells
taking in more nutrients
surface area increases as the ____ of cell radius
square
why are larger animals metabolism slower than smaller animals
the chemical rxns produce heat as a byproduct, an elephants SA:V ration is smaller, so heat would not be able to release the heat
there is a higher SA where
in organs where we take things into the body and where we released things (ex: intestines)
cold temps make phospholipids
a. stiffer
b. softer
c. fluid
a. stiffer
what is metabolism
sum of all rxns in your body
what is catabolism
big compounds broken down into smaller molecules and release energy
what is anabolism
making larger molecules from small and using energy
what are substrates
initial reactants of the rxn
ATP breaks down into ADP and ________
Phosphate
every rxn requires an initial input of ___________
energy
what is activation energy
energy that must be added to start a rxn
which is false about enzymes?
a. they speed up rxns
b. they do not get consumed in a rxn
c. they make activation energy higher
d. enzymes are specific
e. enzymes do not have an active site
f. a and c
g. b and d
h. c and e
h. c and e
why are enzymes specific
bc it has a specific shape to bind substrate to the active site
how do enzymes saturate
add more substrate
if an enzyme changes shape in any way the substrate can/cannot bind
cannot
enzymes present in high levels regardless of conditions
constituitive (always)
what are some factors that can modify enzymatic rxns
- temp: faster in high temps
- pH:extreme pH causes denaturing
- cofactors: help go faster
- competitive/noncompetitive inhibition
what is competitive inhibition
interferes with active site of enzyme so substrate cannot bind
what is noncompetitive inhibition
changes shape of the enzyme so it cannot bind to substrate
what is feedback inhibition
when the product of a pathway acts as an inhibitor of the pathway to prevent too much buildup of a product
transport that does not require energy and takes things down their concentration gradient
passive transport
transport that does require energy and takes things against their concentration gradient
active transport
which are easily diffused through cell membrane
a. ions
b. large, uncharged molecules
c. small, nonpolar molecules
d. small, polar molecules
c. small, nonpolar molecules
once equilibrium is met, molecules will continue to move at random, but the # of molecules moving in both directions will be _______
equal
what is respiration dependent on
gas exchange via diffusion
osmotic pressure is
pressure needed for a pure solvent to not pass into another solution
water always moves from ___ osmotic pressure to ____ osmotic pressure
lower, higher
what is hypertonic
there is a higher concentration of surrounding solution than the cytoplasm
*** shrinks
what is facilitated diffusion
molecules (large, polar, charged) need to pass through selective protein pores- transport proteins
what does the nernst equation tell us
the electrical potential for a single ion to prevent it from having any net movement across the cell membrane
Na+ naturally wants to go in or out of the cell
into
Na+/K+ ATPase transports __ Na ___ and __ K __
3 Na out and 2 K in
Nociceptors detect
pain
which 2 organ systems facilitate communication?
nervous system and endocrine system
Na/K-ATP-ase pumps Enable Na+ and K+ to move from an area of __concentration to an area of ____concentration
low, high
It is ideal to have organisms made up of trillions of small cells compared to few large cells as having a high surface area to volume ratio helps ensure that the surface area is large enough to meet the demands of the volume within the cell and that reactions that occur there.
t/f
true
All of the following are true in regards to ATP except:
a. ATP is needed for the transfer of solutes through the cell membrane with the help of pumps
b. When ATP phosphorylates, the sodium potassium pump releases 2 sodium ions
into the cell
c. ATP is composed of adenine (a nucleotide) and 3 phosphate groups connected to
each other in sequence
d. ATP is not needed for passive transport due to the semi-permeable membrane
allowing small, nonpolar molecules to pass freely down their gradient
b. When ATP phosphorylates, the sodium potassium pump releases 2 sodium ions
into the cell
Match the knerst value to each corresponding ion
a) -88 mV i. Na+
b) -61 mV ii. K+
c) +60 mV iii.Cl
a) ii
b) iii
c) i
Snakes use venom for two main reasons, for protection, and to kill their prey. In class we learned how the venom disrupts blood pressure regulation and makes blood coagulate by interfering with the active site of the enzyme so the substrate can’t bind. Snake venom is an example of a
a) Cofactor
b) Noncompetitive inhibitor
c) Competitive inhibitor
d) Coenzyme
c) Competitive inhibitor
nervous system
-fast or slow?
- targeted or widespread?
-sustained or short lived?
fast
targeted
short lived
at the ________ level, animal nervous systems are very similar
cellular
what is a downside of behavioral complexity
metabolic cost
what are characteristics of more complex nervous systems
- centralized
- cephalized
the CNS consists of
brain and spinal chord
neuroglial cells (2)
a. are electrically excitable
b. make myelin
c. maintain health of the nervous system
d. large cells
e. small cells
c. maintain health of the nervous system
e. small cells
what do ependymal cells do
create and circulate cerebrospinal fluid
what is the difference between Schwann and Oligodendrocytes
schwann makes myelin in PNS and oligo makes myelin in CNS
what are astrocytes
extra layer of protection- wraps around capillaries (blood brain barrier)
which part of the cell decides if the voltage is high enough to fire the action potential?
a. myelin sheath
b. dendrites
c. axon hillock
c. axon hillock
where are neurotransmitters released from
axon terminal
axon moves substances manufactured in the cell body to end of the axon
anterograde
axon moves substances from end of axon to cell body
retrograde
What would happen to the rate of diffusion if the area for gas exchange were to be increased?
a. The rate of diffusion would decrease
b. The rate of diffusion would stay the same
c. The rate of diffusion would increase
d. There is not enough information to answer this question
c. The rate of diffusion would increase
myelin is a fat
T/F
T
what are nodes of ranvier
bare areas with no myelin along axon
at rest, the inside of the cell is
a. positive
b. negative
c. neutral
b. negative
what is the electrical potential due to
- differences in concentration of ions bw intra and extra cellular fluid
- selective permeability of ions across the plasma membrane
the cell membrane has ____ permeability to Na+, and ___ permeability to K+
low, high
is the inside of the cell higher or lower in K
higher K+, lower Na+
The white matter of the brain consists of _______ axons created by _______.
a. Unmyelinated; oligodendrocytes
b. Myelinated; Schwann cells
c. Unmyelinated; Schwann cells
d. Myelinated; oligodendrocytes
d. Myelinated; oligodendrocytes
T/F Both neuropeptides and neurotransmitters are synthesized in the axon terminal.
a. True
b. False
b. false
does an action potential fizzle out as goes down the axon
no
What is NOT a feature of an animal’s nervous system as it gets more complex?
a. Higher metabolic needs
b. Centralization
c. Longer neurons
d. Cephalization
c. Longer neurons
what does the incoming stimulus when about to start an action potential bind to and where
ligand gated ion channel on dendrites
what happens at threshold in an action potential
reaches -55mV and opens the voltage gated ion channels (Na+)
what is depolarization
voltage gets more positive with influx of Na+
which is false about an absolute refractory period?
a. a second action potential can be initiated, it is just harder to
b. a second action potential cannot be initiated
c. Na+ voltage channels are in an inactive state
d. it goes from repolarization until reaches threshold again
a. a second action potential can be initiated, it is just harder to
why do Na+ voltage gated channels deactivate
prevents a reverse propagation of the action potential
the action potential travels down the axon by ______________
saltatory conduction
myelination prevents what during an action potential
ions from leaking out through the membrane
action potentials are regenerated at the next ____________
node of ranvier
what happens in repolarization
K+ voltage gated ion channels open, making the potential go back to negative
more myelin means
faster conduction of action potentials
what does a bigger diameter of axons lead to
faster action potentials bc less resistance to flow of ions
where are neuropeptides made
in the cell body and then gets transported to axon terminal ends
where are ligand gated ion channels located
dendrites
once the AP gets to axon terminal, what happens
stimulates Ca2+ channels
what happens when Ca2+ channels open
Ca2+ ions membranes and vesicle membranes fuse to form holes where neurotransmitters leave
what is the solubility of neurotransmitters
polar= bind to outside of the cell
does the binding of a neurotransmitter always result in depolarization?
no
what is the presynaptic cell
the one that releases the neurotransmitters
Neurotransmitters act at receptors to open ion channels to depolarize or
hyperpolarize
when neurotransmitters act at receptors to hyperpolarize, what is it called
IPSP- inhibitory post synaptic potential
what happens in an IPSP
influx of Cl- molecules (instead of Na+) to make AP less likely to fire
which is false about what the synaptic action of small molecule neurotransmitters is halted by
a. enzymatic destruction
b. reuptake
c. acetylcholine
d. diffusion out of synapse and clean up by astrocytes
c. acetylcholine
how do local anesthetics work
block intracellular portion of Na+ voltage gated channels so no action potential
** no pain signals to brain
what is the afferent division of the PNS
info from this enters the CNS (sensory stimuli)
what 2 divisions does the PNS have
afferent and efferent
what does the efferent division of the PNS do
acts on the signal from CNS
what are the two systems under efferent divisiom
somatic and autonomic
what does the somatic nervous system do
acts on motor neurons to control skeletal muscles
what two subdivisions does the autonomic nervous system contain
sympathetic and parasympathetic
the parasympathetic system
a. rest and digest
b. fight or flight
a. rest and digest
the sympathetic system
a. rest and digest
b. fight or flight
b. fight or flight
what are some common sympathetic system responses
dilate pupils, increase heartbeat, inhibit stomach activity
what are some common parasympathetic system responses
constrict pupils, stimulate saliva, stimulate intestine and stomach, slow heartbeat, constrict airways
what does it mean to say brain function is somewhat localized
it is in a specialized region (one area to process info bc more efficient)
what does it mean to say that brains have maps
more we use something the more neurons it has, more sensitive parts are more used
what does it mean to say brain size matters
more surface area
what does it mean to say there are repeated expansions of the forebrain
the basic life sustaining functions of the brain are lower and there is more personality, cognition, etc
what is neuralplasticity
neurons can sprout new connections (new highway system)
what is the junction between 2 neurons called
synapse
what is a cluster of neuronal cell bodies in the PNS called
ganglion
what is the part of the neuron cell body that lies within the CNS
preganglionic neuron
the axon of the ganglionic neuron extends to visceral organs
postganglionic
the preganglionic axon synapses with the 2nd motor neuron, the ____________
postganglionic neuron
what regions is the sympathetic system from
thoracolumbar- mid back and lower back
what regions is the parasympathetic system from
sacral (genitals) and cranial (brain)
sympathetic release what neurotransmitter
norepinephrine
parasympathetic release what neurotransmitter
acetylcholine
__________ fibers release the neurotransmitter ACh
a. cholinergic
b. adrenergic
a. cholinergic
______ fibers release the neurotransmitter NE- norepinephrine
a. cholinergic
b. adrenergic
b. adrenergic
the sympathetic pathway has ____ preganglia and ____ postganglia
a. long, long,
b. short, long
c. long, short
b. short, long
in the parasympathetic pathway has ____ preganglia and ____ postganglia
a. long, long,
b. short, long
c. long, short
c. long, short
all parasympathetic postganglionic axons release
a. ACh
b. NE
a. ACh
the somatic nervous system has
a. pre and post ganglia
b. one long neuron
b. one long neuron
In our small intestine exists a Na+/glucose cotransporter. This transporter could be classified as
a. Primary active transporter & symporter
b. Secondary active transporter & symporter
c. Passive transporter & antiporter
d. Passive transporter & symporter
b. Secondary active transporter & symporter
two types of cholinergic (ACh) receptors
nicotinic and muscarinic
Neurotransmitter released in the sympathetic pathway in
a. pre ganglia
b. post ganglia
a. ACh
b. NE
Neurotransmitter released in the parasympathetic pathway in
a. pre ganglia
b. post ganglia
a. ACh
b. ACh
in the somatic system, what is the neurotransmitter used
ACh (nicotinic)
in the autonomic system, what is the neurotransmitter used
ACh and NE
in the autonomic system, ACh is used ALWAYS where
at ganglion
nicotinic receptors are used in all _____________ ganglia
autonomic
muscarinic receptors are used at
all parasympathetic EFFECTORS (last step)
where are adrenergic (NE) receptors found
Found in effectors of the
sympathetic NS
what are the 2 types of adrenergic (NE) receptors
alpha and beta 1&2
B1 beta blockers affect
the heart
B2 beta blockers affect
the lungs
Alpha adrenergic receptors affect
smooth muscle contraction
Nicotinc (ach) receptors are present where
Skeletal muscle long neuron and ALL autonomic ganglia
All ACh receptors in ganglia are nicotinic except
Parasympathetic effectors
Hypotonic
Lower concentration than cytoplasm ** bigger
