BIO202 MIDTERM EXAMS ALL QUESTIONS AND
ANSWERS SURE A+
✔✔Functional unit of the muscle cell? What is it made up of? - ✔✔Sarcomere.
Made up of thin (actin) filament and thick (myosin) filament.
Looks like a hotdog
✔✔4 proteins involved in muscle contraction? - ✔✔1) Myosin molecules
2) Actin
3) Tropomyosin
4) Troponin
✔✔Explain the steps of a cross bridge interaction in muscle contractions - ✔✔1)
Troponin active site is exposed when tropomyosin moves, allowing Ca2+ to bind
2) Myosin head in cocked position (ADP and inorganic phosphate (Pi) bound) binds to
actin to make cross bridge
3) In power strike, ADP and Pi break off, allowing myosin head to bend and pull actin
(decreasing I band size)
,4) ATP binds to myosin head to make it detach from actin (cross bridge breaks)
5) ATP hydrolyzes into ADP and Pi to make myosin head go back to cocked position
✔✔As sarcomere length decreases and increases, tension ? - ✔✔Decreases
✔✔Most vertebrate skeletal muscles are ______ muscles and receive signals from a
_______ neuron - ✔✔Neurogenic; motor
✔✔Sarcolemma (plasma membrane of the sarcomere) is rich in what? What are these
used for? - ✔✔Rich in acetylcholine receptors (nicotinic) which aid in excitation-
contraction coupling
✔✔Excitation-contraction coupling - ✔✔Electrical excitation of plasma membrane of
sarcomere leads to activation of a muscle contraction
✔✔Steps of a Excitation-contraction coupling - ✔✔1) From an axon terminal's synaptic
vesicles holding acetylcholine, the molecule is released and binds to nicotinic
(acetylcholine receptors on synaptic cleft)
2) This binding causes an action potential to travel through the T tubule and trigger a
voltage-powered protein on the sarcoplasmic reticulum to change shape and cause a
release of Ca2+
3) Ca2+ goes to bind to troponin, making cross bridges between actin and myosin
4) Enzyme, acetylcholinesterase removes acetylcholine from synaptic cleft, stopping
action potentials, making the protein on the reticulum change to its original shape and
stop release of Ca2+ (Ca2+ is transported BACK INTO the reticulum)
5) Tropomyosin binds to active sites on actin to block them from myosin heads and stop
cross bridge formation
✔✔Transverse Tubules (T tubules) - ✔✔Extensions of plasma membrane that reach
deep into muscle fiber to electrically trigger release of Ca2+ stored in the sarcoplasmic
reticulum. It also binds to the troponin complex to allow cross bridges to form
✔✔4 parts of the spinal cord? - ✔✔1) Cervical (8)
2) Thoracic (12)
3) Lumbar (5)
4) Sacral (5)
✔✔What does the Parasympathetic nervous system do to the following:
a) Pupils
b) Salivation
, c) Heart rate
d) Bronchi
e) Digestion
f) Bile secretion
g) Bladder - ✔✔a) Constricts
b) Stimulates
c) Slows
d) Constricts
e) Stimulates
f) Stimulates
g) Causes bladder to contract
✔✔What does the Sympathetic nervous system do to the following:
a) Pupils
b) Salivation
c) Heart rate
d) Bronchi
e) Digestion
f) Breakdown of glycogen
g) Adrenaline and noradrenaline secretion
h) Bladder - ✔✔a) Dilates
b) Inhibits
c) Increases
d) Dilates
e) Inhibits
f) Stimulates
g) Stimulates
h) Inhibits contraction of bladder
✔✔Answer the following about the Sympathetic pathway of neurons:
a) Preganglionic neuron soma is located where?
b) Postganglionic neuron soma is in a ____ located next to the ____?
c) Which neurotransmitters are released from the preganglionic synpase?
d) Which neurotransmitters are released from the postganglionic synpase?
e) Targets what response? - ✔✔a) Usually in spine
b) Sympathetic ganglion, located next to spinal cord
c) Acetylcholine
d) Norepinephrine
e) Fight or flight response
✔✔Answer the following about the Parasympathetic pathway of neurons:
a) Preganglionic neuron soma is located where?
b) Postganglionic neuron soma is in a ____ located next to the ____?
c) Which neurotransmitters are released from the preganglionic synpase?
d) Which neurotransmitters are released from the postganglionic synpase?
ANSWERS SURE A+
✔✔Functional unit of the muscle cell? What is it made up of? - ✔✔Sarcomere.
Made up of thin (actin) filament and thick (myosin) filament.
Looks like a hotdog
✔✔4 proteins involved in muscle contraction? - ✔✔1) Myosin molecules
2) Actin
3) Tropomyosin
4) Troponin
✔✔Explain the steps of a cross bridge interaction in muscle contractions - ✔✔1)
Troponin active site is exposed when tropomyosin moves, allowing Ca2+ to bind
2) Myosin head in cocked position (ADP and inorganic phosphate (Pi) bound) binds to
actin to make cross bridge
3) In power strike, ADP and Pi break off, allowing myosin head to bend and pull actin
(decreasing I band size)
,4) ATP binds to myosin head to make it detach from actin (cross bridge breaks)
5) ATP hydrolyzes into ADP and Pi to make myosin head go back to cocked position
✔✔As sarcomere length decreases and increases, tension ? - ✔✔Decreases
✔✔Most vertebrate skeletal muscles are ______ muscles and receive signals from a
_______ neuron - ✔✔Neurogenic; motor
✔✔Sarcolemma (plasma membrane of the sarcomere) is rich in what? What are these
used for? - ✔✔Rich in acetylcholine receptors (nicotinic) which aid in excitation-
contraction coupling
✔✔Excitation-contraction coupling - ✔✔Electrical excitation of plasma membrane of
sarcomere leads to activation of a muscle contraction
✔✔Steps of a Excitation-contraction coupling - ✔✔1) From an axon terminal's synaptic
vesicles holding acetylcholine, the molecule is released and binds to nicotinic
(acetylcholine receptors on synaptic cleft)
2) This binding causes an action potential to travel through the T tubule and trigger a
voltage-powered protein on the sarcoplasmic reticulum to change shape and cause a
release of Ca2+
3) Ca2+ goes to bind to troponin, making cross bridges between actin and myosin
4) Enzyme, acetylcholinesterase removes acetylcholine from synaptic cleft, stopping
action potentials, making the protein on the reticulum change to its original shape and
stop release of Ca2+ (Ca2+ is transported BACK INTO the reticulum)
5) Tropomyosin binds to active sites on actin to block them from myosin heads and stop
cross bridge formation
✔✔Transverse Tubules (T tubules) - ✔✔Extensions of plasma membrane that reach
deep into muscle fiber to electrically trigger release of Ca2+ stored in the sarcoplasmic
reticulum. It also binds to the troponin complex to allow cross bridges to form
✔✔4 parts of the spinal cord? - ✔✔1) Cervical (8)
2) Thoracic (12)
3) Lumbar (5)
4) Sacral (5)
✔✔What does the Parasympathetic nervous system do to the following:
a) Pupils
b) Salivation
, c) Heart rate
d) Bronchi
e) Digestion
f) Bile secretion
g) Bladder - ✔✔a) Constricts
b) Stimulates
c) Slows
d) Constricts
e) Stimulates
f) Stimulates
g) Causes bladder to contract
✔✔What does the Sympathetic nervous system do to the following:
a) Pupils
b) Salivation
c) Heart rate
d) Bronchi
e) Digestion
f) Breakdown of glycogen
g) Adrenaline and noradrenaline secretion
h) Bladder - ✔✔a) Dilates
b) Inhibits
c) Increases
d) Dilates
e) Inhibits
f) Stimulates
g) Stimulates
h) Inhibits contraction of bladder
✔✔Answer the following about the Sympathetic pathway of neurons:
a) Preganglionic neuron soma is located where?
b) Postganglionic neuron soma is in a ____ located next to the ____?
c) Which neurotransmitters are released from the preganglionic synpase?
d) Which neurotransmitters are released from the postganglionic synpase?
e) Targets what response? - ✔✔a) Usually in spine
b) Sympathetic ganglion, located next to spinal cord
c) Acetylcholine
d) Norepinephrine
e) Fight or flight response
✔✔Answer the following about the Parasympathetic pathway of neurons:
a) Preganglionic neuron soma is located where?
b) Postganglionic neuron soma is in a ____ located next to the ____?
c) Which neurotransmitters are released from the preganglionic synpase?
d) Which neurotransmitters are released from the postganglionic synpase?
