Answer:
When a muscle cell contracts, the myosin heads each produce a single power stroke.
Explanation:
In rest, attraction strengths between myosin and actin filaments are inhibited by the tropomyosin. When the muscle fiber membrane depolarizes, the action potential caused by this depolarization enters the t-tubules depolarizing the inner portion of the muscle fiber. This activates calcium channels in the T tubules membrane and releases calcium into the sarcolemma. At this point, <em>tropomyosin is obstructing binding sites for myosin on the thin filament</em>. When calcium binds to the troponin C, the troponin T alters the tropomyosin by moving it and then unblocks the binding sites. Myosin heads bind to the uncovered actin-binding sites forming cross-bridges, and while doing it ATP is transformed into ADP and inorganic phosphate which is liberated. Myofilaments slide impulsed by chemical energy collected in myosin heads, <u>producing a power stroke</u>. The power stroke initiates when the myosin cross-bridge binds to actin. As they slide, ADP molecules are released. A new ATP links to myosin heads and breaks the bindings to the actin filament. Then ATP splits into ADP and phosphate, and the energy produced is accumulated in the myosin heads, which starts a new binding cycle to actin. Z-bands are then pulled toward each other, thus shortening the sarcomere and the I-band, and producing muscle fiber contraction.
Answer:
since only 10% is passed you multiple the number given by .10
Explanation:
so 35,000*.10=3500 which is the first blank and you multiply that by .10 to get 350 and thats the second blank, then do that again to get 35 and then again and you get 3.5
Options for the question have not been given. They are as follows:
blood vessel length
blood viscosity
blood vessel diameter
blood colloid osmotic pressure
Answer:
blood colloid osmotic pressure
Explanation:
- Peripheral resistance is the resistance to blood flow by blood vessels.
- It is directly proportional to blood vessel length as more the distance to travel, more will be the resistance.
- It is also directly proportional to blood viscosity as more energy is required to push viscous material.
- It is indirectly proportional to blood vessel diameter. More the diameter of the vessel, easier it is for the blood to pass.
- However, it does not depend on blood colloid osmotic pressure. Colloid osmotic pressure is created by the protein components of blood and they do not have any direct impact on blood flow.
The proteins are called Histone proteins. Chromosomal DNA is packaged such that the strands of DNA are wound around histone proteins and fold into complex ways to form chromosomes. The histone proteins are positively charged proteins that strongly adhere to negatively charged DNA and form complexes called nucleosomes. Each nucleosome is composed of double-helical DNA wrapped.
The best and most correct answer among the choices provided by the question is <span>b. oil</span> <span>.
</span>A thick, black liquid formed from the buried remains of microscopic marine organisms is oil .
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Hope my answer would be a great help for you. </span>
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