1.2 -- muscles/sliding filament theory (SFT)

Question 1

actin

Answer 1

thin filament of the skeletal muscle

Question 2

myosin

Answer 2

thick filament of the skeletal muscle

Question 3

ATP (adenosine triphosphate)

Answer 3

main energy source that muscle cells use for most of their work

Question 4

calcium ions

Answer 4

bind to the protein that blocks the myosin-binding sites on actin. serves as the actual “trigger” for muscle contraction.

Question 5

troponin

Answer 5

regulatory protein that binds to actin, tropomyosin, & calcium

Question 6

tropomyosin

Answer 6

covers myosin binding sites on the actin molecules during muscle contraction

Question 7

neuromuscular junction (NMJ)

Answer 7

synapse between a neuron & a skeletal fiber, ACh goes through this junction to the muscle fiber

Question 8

sarcoplasmic reticulum

Answer 8

organelle of the muscle fiber that stores calcium & releases it during muscle contraction

Question 9

t-tubule

Answer 9

a structure that sends the impulse from the receptors to the sarcoplasmic reticulum

Question 10

motor neuron

Answer 10

a neuron that sends an impulse to a muscle causing it to react

Question 11

ACh (acetylcholine)

Answer 11

a neurotransmitter that enables muscle action, learning, & memory

Question 12

sarcomere

Answer 12

contractile unit of a muscle fiber