The function of ATP during muscle contraction is to
A. Causes a conformational change in myosin so that it detaches from actin
B. Provide the energy necessary to release calcium from the sarcoplasmic reticulum
C. Expose the myosin-binding sites on the filaments
D. Cause shortening of the H zone of the sarcomere
Causes a conformational change in myosin so that it detaches from actin
The role of calcium in skeletal muscle contraction is to
A. Cause a conformational change in myosin so that it releases from actin
B. Expose the myosin binding site
C. Promote the repolarization of the nerve cell after it has depolarized the muscle cell.
D. Activate the ATPase in the sarcoplasmic reticulum.
Expose the myosin binding site
The marrow cavity of an adult bone may contain
A. Hyaline cartilage
C. Blood forming tissue
E. Epiphyseal cartilage
Blood forming tissue
Stimulation of a muscle fiber by a motor neuron occurs at
A. The neuromuscular junction
B. The transverse tubules
C. The myofibril
D. The sarcoplasmic reticulum
The neuromuscular junction
When I make chicken soup, I always put a bit of vinegar in it, which helps to release Ca2+ from the bones. How does this work?
A. it activates osteoclasts.
B. it activates osteoblasts.
C. it dissolves the bone minerals.
D. it opens Ca2+ channels in the sarcoplasmic reticulum
it dissolves the bone minerals.
Curare, a substance that blocks the acetylcholine receptors on skeletal muscle, will cause
A. Rapid muscle twitches
B. Sustained muscle contraction
C. Muscle relaxation
D. Disruption of blood pressure and digestive functions
E. No effect, as acetylcholinesterase will degrade it
Slow twitch fibers have all of the following EXCEPT
A. An abundance of myoglobin
B. A well-developed glycolysis/lactic acid system
C. High fatigue resistance
D. A red color
E. A high capacity to synthesize ATP aerobically
A well-developed glycolysis/lactic acid system
A boy takes a ski jump and lands on hard ice. The reason his bones do not shatter is because they contain
A. An abundance of calcium phosphate
B. Young, resilient osteocytes
C. Myosin fibers
D. Collagen fibers
E. Elastin fibers
which of the following decreases in size during muscle contraction
- I Band
- A Band
- H zone
- Z line
Does the length of myosin and actin decrease when a muscle contracts
no they overlap
Where is the sorage of O2 in the muscle
in the myoglobin