Bio E109 Midterm 1 Questions and Answers
Question 1.
Subthreshold graded potential
Correct Answer: A graded potential starts above threshold at its initiation point
but decreases in strength as it travels through the cell body. At the tigger zoned
it is below threshold and therefore does not initiate an action potential
Question 2.
L1 - what is hyperosmotic?
Correct Answer: Having MORE particles that's osmotically active in a soln than
its counterpart Review slide 17 of lecture 1
Question 3.
Thin filaments regulation
Correct Answer: Tropomyosin, myosin head cannot interact with the action
potential because it is in the way When calcium comes in to bind to troponin
tropomyosin moves and head can interact with action potential
Question 4.
L5 - What is the LIGAND (gonna be a hormone/NT) that binds and activates ADRENER- GIC
receptors?
Correct Answer: epinephrine and norepinephrine
Question 5.
L4 - How are graded potentials depolarized and hyperpolarized?
Correct Answer: - Inhibitory postsynaptic potential (IPSP) HYPERPOLARIZE -
Excitatory postsynaptic potentials (EPSP) DEPOLARIZE
Question 6.
End muscle contraction
Correct Answer: Calcium removed from cytoplasm and put back to cytoplasmic
reticulum
Question 7.
L5 - Do Schwann cells make up myelin sheath in CNS/PNS?
Correct Answer: Peripheral nervous system
Question 8.
How are calcium ions returned to the sarcoplasmic reticulum
Correct Answer: The action of calcium ATPase
Question 9.
L5 - What is the function of the pons?
Correct Answer: relays info between cerebellum and cerebrum (functions in
respiratory control)
,Question 10.
L2 - How do negative feedback loops work?
Correct Answer: the response of the initial stimulus goes back to decrease/block
the stimulus from happening further -the response acts as the control
Question 11.
L8 - What are smooth muscle cells innervated (stimulated) by?
Correct Answer: the autonomic nervous system (ANS)
Question 12.
L1 - What is homeostasis?
Correct Answer: the process of maintaining a RELATIVELY constant internal
environment can't be always constant because molecules always move and
concentrations always change
Question 13.
L3 - What is equilibrium potential? (Nernst equation to calculate EQ potential of an ion)
Correct Answer: The membrane potential of the neuron at which equilibrium
occurs
Question 14.
L5 - Do BOTH PNS and SNS release Ach (acetylcholine)?
Correct Answer: YES! at the nicotinic receptor site, which will go to activate the
release of EPINEPH- RINE/NOREPINEPHRINE (for SNS) and MORE ACETYLCHOLINE
(for PNS)
Question 15.
L2 - What is a preprohormone?
Correct Answer: large and inactive precursor peptides that gets packaged into
vesicles of the Golgi to go to the ER and gets cleaved by enzymes to be made
into prohormones to be further cleaved into a hormone
Question 16.
Hormone
Correct Answer: Compound released from one tissue, travels to another tissue
through bloodstream
Question 17.
L8 - How does ANS innervate (stimulate) a smooth muscle, if not by a single axon
terminal/synapse?
Correct Answer: the axon OF THE POSTGANGLIONIC AUTONOMIC NEURON is
expanded to varicosities that surround the smooth muscle
Question 18.
L1 - what is osmosis?
Correct Answer: the diffusion of water from higher concentration (of water) to
lower concentration of water or it's the diffusion from lower concentration of
solutes to higher concentration of solutes
,Question 19.
L3 - how is potassium maintained in higher concentration INSIDE the cell during resting
phase?
Correct Answer: sodium-potassium ATPase pump
Question 20.
L7 - What are the roles of Ca2+ and ATP in muscle contraction
Correct Answer: - ATP only releases myosin from actin binding site - Ca2+ allows
myosin to bind to actin
Question 21.
L3 - Which of the nervous system delivers input signals to the integrating center?
Correct Answer: Dendrites
Question 22.
L1 - what are the 4 categories of membrane receptors?
Correct Answer: receptor channels G-protein-coupled receptors catalytic
receptors: receptor enzyme and integrin receptor
Question 23.
L8 - How do multi-unit smooth muscle cells contract/relax?
Correct Answer: different neurotransmitters must be released at different parts
to regulate contractions independently
Question 24.
L2 - How does change in hypothalamus-pituitary-target cell axis change hormone
concentration?
Correct Answer: mutation in or down-regulation of target cell receptor can lead
to hyper- or hypo-secretion of hormones.
Question 25.
Where do calcium ions exit in muscles
Correct Answer: Sarcoplasmic reticulum through calcium ion channels
Question 26.
In muscles the action potential runs thru...
Correct Answer: Sarcolemma and t-tubules
Question 27.
Absolute refractory period
Correct Answer: Period of time where the sodium channels cannot respond or
reopen
Question 28.
L7 - what are the up and downsides of glycolysis in ATP production?
Correct Answer: advantages: occur without oxygen (fast ATP) disadvantages:
inefficient (only makes 2 ATPs)
, Question 29.
L8 - What stimuli can trigger a smooth muscle cell to contract?
Correct Answer: Signal ligands via membrane receptors and membrane
channels, depolarization/stretch
Question 30.
L7 - What is a motor unit?
Correct Answer: consists of 1 motor neuron and ALL of the muscle fibers it
INNERVATES (stimulates)
Question 31.
L3 - What is the function of myelin?
Correct Answer: insulation of the axon as the axon transmits its electrical
message, which will increase propagation speed.
Question 32.
What is the muscle membrane called
Correct Answer: Sarcolemma
Question 33.
L7 - What is summation?
Correct Answer: If an action potential comes RIGHT before the previous action
potential enters HYPERPOLARIZATION, the muscle generates higher amount of
force
Question 34.
Interstitial fluid composed of...
Correct Answer: Sodium Chloride, bicarbonate Low protein
Question 35.
L7 - What happens to myosin and actin when muscles relaxes?
Correct Answer: 1. Myosin detaches from actin filaments 2. Titin proteins allow
motor proteins to resume resting conformation
Question 36.
L5 - Describe the steps and pathways involved in regulating body temperature at
homeostatic set point
Correct Answer: if it's too cold, increase thyroid hormone to release basal
metabolic rate to generate heat; behavioral adjustments (move to warmth)
Question 37.
Bipolar neuron
Correct Answer: Two processes, the axon and dendrite
Question 38.
L7 - What happens when there's TOO MUCH TENSION (too little thick and thin filaments
overlap) in a muscle?
Correct Answer: too much tension = fewer myosin heads to attach to the actin
and engage in cross bridge cycle --> SUB-OPTIMAL overlap --> could lead to NO
myosin-actin overlap and no sarcomeres shortening ex: if arm is raised above
Question 1.
Subthreshold graded potential
Correct Answer: A graded potential starts above threshold at its initiation point
but decreases in strength as it travels through the cell body. At the tigger zoned
it is below threshold and therefore does not initiate an action potential
Question 2.
L1 - what is hyperosmotic?
Correct Answer: Having MORE particles that's osmotically active in a soln than
its counterpart Review slide 17 of lecture 1
Question 3.
Thin filaments regulation
Correct Answer: Tropomyosin, myosin head cannot interact with the action
potential because it is in the way When calcium comes in to bind to troponin
tropomyosin moves and head can interact with action potential
Question 4.
L5 - What is the LIGAND (gonna be a hormone/NT) that binds and activates ADRENER- GIC
receptors?
Correct Answer: epinephrine and norepinephrine
Question 5.
L4 - How are graded potentials depolarized and hyperpolarized?
Correct Answer: - Inhibitory postsynaptic potential (IPSP) HYPERPOLARIZE -
Excitatory postsynaptic potentials (EPSP) DEPOLARIZE
Question 6.
End muscle contraction
Correct Answer: Calcium removed from cytoplasm and put back to cytoplasmic
reticulum
Question 7.
L5 - Do Schwann cells make up myelin sheath in CNS/PNS?
Correct Answer: Peripheral nervous system
Question 8.
How are calcium ions returned to the sarcoplasmic reticulum
Correct Answer: The action of calcium ATPase
Question 9.
L5 - What is the function of the pons?
Correct Answer: relays info between cerebellum and cerebrum (functions in
respiratory control)
,Question 10.
L2 - How do negative feedback loops work?
Correct Answer: the response of the initial stimulus goes back to decrease/block
the stimulus from happening further -the response acts as the control
Question 11.
L8 - What are smooth muscle cells innervated (stimulated) by?
Correct Answer: the autonomic nervous system (ANS)
Question 12.
L1 - What is homeostasis?
Correct Answer: the process of maintaining a RELATIVELY constant internal
environment can't be always constant because molecules always move and
concentrations always change
Question 13.
L3 - What is equilibrium potential? (Nernst equation to calculate EQ potential of an ion)
Correct Answer: The membrane potential of the neuron at which equilibrium
occurs
Question 14.
L5 - Do BOTH PNS and SNS release Ach (acetylcholine)?
Correct Answer: YES! at the nicotinic receptor site, which will go to activate the
release of EPINEPH- RINE/NOREPINEPHRINE (for SNS) and MORE ACETYLCHOLINE
(for PNS)
Question 15.
L2 - What is a preprohormone?
Correct Answer: large and inactive precursor peptides that gets packaged into
vesicles of the Golgi to go to the ER and gets cleaved by enzymes to be made
into prohormones to be further cleaved into a hormone
Question 16.
Hormone
Correct Answer: Compound released from one tissue, travels to another tissue
through bloodstream
Question 17.
L8 - How does ANS innervate (stimulate) a smooth muscle, if not by a single axon
terminal/synapse?
Correct Answer: the axon OF THE POSTGANGLIONIC AUTONOMIC NEURON is
expanded to varicosities that surround the smooth muscle
Question 18.
L1 - what is osmosis?
Correct Answer: the diffusion of water from higher concentration (of water) to
lower concentration of water or it's the diffusion from lower concentration of
solutes to higher concentration of solutes
,Question 19.
L3 - how is potassium maintained in higher concentration INSIDE the cell during resting
phase?
Correct Answer: sodium-potassium ATPase pump
Question 20.
L7 - What are the roles of Ca2+ and ATP in muscle contraction
Correct Answer: - ATP only releases myosin from actin binding site - Ca2+ allows
myosin to bind to actin
Question 21.
L3 - Which of the nervous system delivers input signals to the integrating center?
Correct Answer: Dendrites
Question 22.
L1 - what are the 4 categories of membrane receptors?
Correct Answer: receptor channels G-protein-coupled receptors catalytic
receptors: receptor enzyme and integrin receptor
Question 23.
L8 - How do multi-unit smooth muscle cells contract/relax?
Correct Answer: different neurotransmitters must be released at different parts
to regulate contractions independently
Question 24.
L2 - How does change in hypothalamus-pituitary-target cell axis change hormone
concentration?
Correct Answer: mutation in or down-regulation of target cell receptor can lead
to hyper- or hypo-secretion of hormones.
Question 25.
Where do calcium ions exit in muscles
Correct Answer: Sarcoplasmic reticulum through calcium ion channels
Question 26.
In muscles the action potential runs thru...
Correct Answer: Sarcolemma and t-tubules
Question 27.
Absolute refractory period
Correct Answer: Period of time where the sodium channels cannot respond or
reopen
Question 28.
L7 - what are the up and downsides of glycolysis in ATP production?
Correct Answer: advantages: occur without oxygen (fast ATP) disadvantages:
inefficient (only makes 2 ATPs)
, Question 29.
L8 - What stimuli can trigger a smooth muscle cell to contract?
Correct Answer: Signal ligands via membrane receptors and membrane
channels, depolarization/stretch
Question 30.
L7 - What is a motor unit?
Correct Answer: consists of 1 motor neuron and ALL of the muscle fibers it
INNERVATES (stimulates)
Question 31.
L3 - What is the function of myelin?
Correct Answer: insulation of the axon as the axon transmits its electrical
message, which will increase propagation speed.
Question 32.
What is the muscle membrane called
Correct Answer: Sarcolemma
Question 33.
L7 - What is summation?
Correct Answer: If an action potential comes RIGHT before the previous action
potential enters HYPERPOLARIZATION, the muscle generates higher amount of
force
Question 34.
Interstitial fluid composed of...
Correct Answer: Sodium Chloride, bicarbonate Low protein
Question 35.
L7 - What happens to myosin and actin when muscles relaxes?
Correct Answer: 1. Myosin detaches from actin filaments 2. Titin proteins allow
motor proteins to resume resting conformation
Question 36.
L5 - Describe the steps and pathways involved in regulating body temperature at
homeostatic set point
Correct Answer: if it's too cold, increase thyroid hormone to release basal
metabolic rate to generate heat; behavioral adjustments (move to warmth)
Question 37.
Bipolar neuron
Correct Answer: Two processes, the axon and dendrite
Question 38.
L7 - What happens when there's TOO MUCH TENSION (too little thick and thin filaments
overlap) in a muscle?
Correct Answer: too much tension = fewer myosin heads to attach to the actin
and engage in cross bridge cycle --> SUB-OPTIMAL overlap --> could lead to NO
myosin-actin overlap and no sarcomeres shortening ex: if arm is raised above
