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:
Here gulcose, maltose, and fructose are carbohydrate. Glycine is not a carbohydrate
Explanation:
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<u>Answer:</u>
<em>The dissolved gases produce violent eruption as they escape.
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<u>Explanation:</u>
Magma contains dissolved gases and these dissolved gases induce vapor <em>pressure on the magma.</em> The magma is able to remain in the dissolved state itself without erupting because this vapor pressure is less than the confining pressure of the <em>rock surrounding the magma. </em>
One the vapor pressure exceeds this confining pressure the dissolved gases begin to expand and<em> forms small gas bubbles</em>.
The <em>density of these gas bubbles</em> called vesicles is less than the density of magma and thus naturally tries to push out. When the gas bubbles escape the magma is also pushed out. Thus greater <em>amount of dissolved gases result in violent eruptions.
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Answer:
Cross bridge in a sarcomere of a fast fiber produce higher amounts of force as compared to a cross bridge in a sarcomere of a slow fiber
Explanation:
When a muscle contracts, a cross bridge is formed between actin and myosin. The sarcomere shortens when a muscle contracts by reforming cross bridge. In general a muscle fiber is of three types – a) slow, b) Fast and c) intermediate.
The sarcomere of fast fiber generates high force but for a short period of time. On the other hand, sarcomere of slow fiber generate lower amounts of force but this force lasts for a longer period of time. Due to this difference, fast fibers are the predominant fibers in the body
There are more but birds would be a bad index fossils
I hope this helps!
