BIO 330 EXAM 3 QUESTIONS AND ANSWERS UPDATED 2024/2025 A
COMPLETE SOLUTION ALL ANSWERS CORRECT DETAILED BEST
GRADED TO SCORE A+ FOR PASS
SKELETAL muscle cells have
a. branched cells
b. gap junctions
c. uni-nucleated cells
d. transverse tubules
e. all of the above - CORRECT ANSWERS d. transverse tubules
Which is the most correct statement? In skeletal muscle, the protein titin
a. runs the entire length of the actin filament
b. runs the entire length of the myosin filament
c. runs only from the end of myosin filament to the Z disk
d. runs from the end of actin filament to the M-line
e. runs along wrapping around the long wire-like nebulin protein - CORRECT ANSWERS
b. runs the entire length of the myosin filament
Which is NOT a role for ATP in SKELETAL muscle cells?
a. energizing the CB head allowing it to bind and move the attached filament
b. modulating the CB head allowing it to unbind from the attached filament
c. used to gate RYR Ca2+ ion channels in the sarcoplasmic reticulum
d. used by Calcium-ion pumps to move Ca2+ into the sarcoplasmic reticulum
e. used by Na+/K+ ion pumps in the cell membrane - CORRECT ANSWERS c. used to
gate RYR Ca2+ ion channels in the sarcoplasmic reticulum
Which is a FALSE statement about a CB cycle and the four steps of the cycle?
a. binding of ATP causes myosin head to detach via allosteric modulation
b. ATP is needed to phosphorylate the myosin head to cause the head to detach
, BIO 330 EXAM 3 QUESTIONS AND ANSWERS UPDATED 2024/2025 A
COMPLETE SOLUTION ALL ANSWERS CORRECT DETAILED BEST
GRADED TO SCORE A+ FOR PASS
c. phosphorylation causes myosin to bend and able to bind the thin filament
d. release of phosphate ion from myosin causes the "power stroke"
e. the power stroke moves or "slides" the attached thin filament - CORRECT ANSWERS
b. ATP is needed to phosphorylate the myosin head to cause the head to detach
in SKELETAL muscle, Cross bridge activity (CB cycling) requires
a. myosin light chain is phosphorylated, which activates actin-binding site on myosin
b. myosin light chain is phosphorylated, which activates myosin-binding site on actin
c. Ca2+ ion channels to open to let in extracellular calcium to regulate CB cycling
d. sufficient Ca2+ ion binding to troponin, so myosin-binding sites on actin will become
unblocked
e. sufficient Ca2+ ion binding to tropomyosin, so myosin-binding on actin sites are unblocked -
CORRECT ANSWERS d. sufficient Ca2+ ion binding to troponin, so myosin-binding sites
on actin will become unblocked
In STRIATED muscle cells, some CB cycling can begin if some
a. calmodulins bind Ca2+ ions.
b. nebulins are compressed.
c. troponins shift position uncovering the underlying binding sites for the CB "heads".
d. tropomyosins move, uncovering binding sites for the CB "heads".
e. Ca2+ ions are allowed to diffuse out of the cell into the extracellular fluid. - CORRECT
ANSWERS d. tropomyosins move, uncovering binding sites for the CB "heads".
Which is FALSE? In CARDIAC muscle cells there are
a. transverse tubules projecting into the cell
b. myofilaments arranged into sarcomeres
c. relatively smaller terminal cisternae
COMPLETE SOLUTION ALL ANSWERS CORRECT DETAILED BEST
GRADED TO SCORE A+ FOR PASS
SKELETAL muscle cells have
a. branched cells
b. gap junctions
c. uni-nucleated cells
d. transverse tubules
e. all of the above - CORRECT ANSWERS d. transverse tubules
Which is the most correct statement? In skeletal muscle, the protein titin
a. runs the entire length of the actin filament
b. runs the entire length of the myosin filament
c. runs only from the end of myosin filament to the Z disk
d. runs from the end of actin filament to the M-line
e. runs along wrapping around the long wire-like nebulin protein - CORRECT ANSWERS
b. runs the entire length of the myosin filament
Which is NOT a role for ATP in SKELETAL muscle cells?
a. energizing the CB head allowing it to bind and move the attached filament
b. modulating the CB head allowing it to unbind from the attached filament
c. used to gate RYR Ca2+ ion channels in the sarcoplasmic reticulum
d. used by Calcium-ion pumps to move Ca2+ into the sarcoplasmic reticulum
e. used by Na+/K+ ion pumps in the cell membrane - CORRECT ANSWERS c. used to
gate RYR Ca2+ ion channels in the sarcoplasmic reticulum
Which is a FALSE statement about a CB cycle and the four steps of the cycle?
a. binding of ATP causes myosin head to detach via allosteric modulation
b. ATP is needed to phosphorylate the myosin head to cause the head to detach
, BIO 330 EXAM 3 QUESTIONS AND ANSWERS UPDATED 2024/2025 A
COMPLETE SOLUTION ALL ANSWERS CORRECT DETAILED BEST
GRADED TO SCORE A+ FOR PASS
c. phosphorylation causes myosin to bend and able to bind the thin filament
d. release of phosphate ion from myosin causes the "power stroke"
e. the power stroke moves or "slides" the attached thin filament - CORRECT ANSWERS
b. ATP is needed to phosphorylate the myosin head to cause the head to detach
in SKELETAL muscle, Cross bridge activity (CB cycling) requires
a. myosin light chain is phosphorylated, which activates actin-binding site on myosin
b. myosin light chain is phosphorylated, which activates myosin-binding site on actin
c. Ca2+ ion channels to open to let in extracellular calcium to regulate CB cycling
d. sufficient Ca2+ ion binding to troponin, so myosin-binding sites on actin will become
unblocked
e. sufficient Ca2+ ion binding to tropomyosin, so myosin-binding on actin sites are unblocked -
CORRECT ANSWERS d. sufficient Ca2+ ion binding to troponin, so myosin-binding sites
on actin will become unblocked
In STRIATED muscle cells, some CB cycling can begin if some
a. calmodulins bind Ca2+ ions.
b. nebulins are compressed.
c. troponins shift position uncovering the underlying binding sites for the CB "heads".
d. tropomyosins move, uncovering binding sites for the CB "heads".
e. Ca2+ ions are allowed to diffuse out of the cell into the extracellular fluid. - CORRECT
ANSWERS d. tropomyosins move, uncovering binding sites for the CB "heads".
Which is FALSE? In CARDIAC muscle cells there are
a. transverse tubules projecting into the cell
b. myofilaments arranged into sarcomeres
c. relatively smaller terminal cisternae
