Muscles
Formed by supporting proteins holding thick filaments together in the center of the H zone.
M line
12) Smaller structures within myofibrils.
Filaments
Serves as storage form of glucose; can be broken down and used to synthesize ATP.
Glycogen
Center of the A band; contains only thick filaments.
H zone
Contains only thin filaments.
I band
Entire length of the thick filament; contains area of overlap with thin filament.
A bands
connects a Z disc to the M line of a sarcomere, helping stabilize the position of the thick filament.
titin
Proteins that are considered structural proteins.
titin alfa actine, myomesin, nebulin, dystophin
Proteins that are considered regulatory proteins.
tropomoysin and troponin
this protein is a component of the thin filament that will cover the myosin-binding sites on the actin molecules.
tropomyosin
this protein is a component of the thin filament and is where calcium ions will bind to during skeletal muscle contraction.
troponin
A fiber is categorized as slow or fast depending on how rapidly the ATPase in its myosin heads hydrolyze ATP
true
Fast glycolytic fibers have low myoglobin content, few blood capillaries, few mitochondria, and appear white in color.
true
Fast oxidative- glycolytic fibers are fast-twitch fibers adapted for intense movements of short duration like weight lifting or throwing a ball.
true
Fast oxidative- glycolytic fibers have a high intracellular glycogen level, which allows them to generate ATP by aerobic respiration.
true
Skeletal muscle fibers that have a high myoglobin content are termed red muscle fibers
true
Slow oxidative fibers are smallest in diameter and are the least powerful type of muscle fibers.
true
Slow oxidative fibers generate ATP mainly by aerobic respiration
true
Contractile element of the skeletal muscle fiber; containing thick and thin filaments
Myofibril
Red, oxygen binding protein that is only found in the muscle; stores oxygen until it is needed by mitochondria for ATP.
Myoglobin
storage center for calcium in relaxed muscle.
Sarcoplasmic reticulum
Invaginations of the sarcolemma; filled with extracellular fluid.
T tubules
2) Narrow, plate shaped regions of dense protein.
Z discs
main component of the thin filament that has an active myosin-binding site.
actin
present in the Z discs, it will attach to actin and titin molecules.
alpha actinin
Ability of muscle to contract forcefully when adequately stimulated
contractility
links thin filaments of the sarcomere to integral membrane proteins in the sarcolemma. This might help transmit the tension generated by sarcomeres to tendons.
dystrophin
Ability of muscle to return to its original length and shape after contraction or extension
elasticity
Ability to respond to certain stimuli by producing action potentials
electrical excitability
Match each muscle property with its correct definition. Ability of muscle to stretch without being damaged
externsibility
Fast glycolytic fibers are intermediate in diameter and have a high resistance to fatigue
false
Match the terms to their definition/function Plasma membrane of a muscle fiber.
sacromere
Repeating units of a myofibril.
sacromere
Surrounded by the sarcolemma; the cytoplasm of the muscle fiber.
sacroplasm
Proteins that are considered contractile proteins.
myosin & actin
wraps around the entire length of each thin filament. It also helps to anchor thin filaments to Z discs in addition to regulating the length of thin filaments during development.
nebulin
Formed by transverse tubules and two terminal cisternae.
Triad
forms the M line of the sarcomere. It also binds to titin molecules and connects adjacent thick filaments to one another.
myomesin
makes up the thick filaments. It consists of two heads and a tail.
myosin