ISSA Nutritionist: Unit 5 Flashcards
myofibrils
One of the threadlike components of a muscle fiber
myosin
Thick fibrous muscle protein that can split ATP and bind with actin
actin
Thin fibrous muscle protein that is necessary for cell shape and can bind to myosin
cross-bridges
Formed when the head of the myosin temporarily attaches to actin
Sarcomeres
are made of strands of actin and myosin attached to natural breaks in the muscle, called Z-discs. If you look at muscle under a microscope, you’ll see that it looks striated. That characteristic appearance comes from the Z-discs.
Z-discs
Region of the sarcomere into which actin is inserted
myoglobin
Oxygen-carrying and storage protein of muscle. Similar to hemoglobin
metabolic testing
Tests that measure metabolic functions (e.g., digestion and energy production)
MET
Oxygen cost of energy expenditure measured at rest, equal to 3.5 mL of oxygen per kilogram of body weight per minute
oxygen deficit
Difference between oxygen uptake of the body during early exercise and during a similar duration of steady-state exercise
oxygen debt
Extra oxygen required above basal needs after a period of intense exercise
EPOC (excess post-exercise oxygen consumption)
Increased rate of oxygen uptake following strenuous activity
muscle hypertrophy
Increase in the size of muscle cells
myofibrillar hypertrophy
Enlargement of a muscle fiber as it gains myofibrils
sarcoplasmic hypertrophy
Increase in the volume of the sarcoplasmic fluid in the muscle cell with no concurrent increase in strength
