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.
I think it’s listed in largest to smallest order as is.
A biome is a large community of plants and animals that is in a area with a distinct region. There are 5 major types of biomes worldwide. These are aquatic, desert, forest, grassland, and tundra. Hope this answers the question. Have a nice day.
<span>The answer is D. Both fungi and plants can
grow in soil.</span>
<span>
Through the process of elimination:
- Plants are autotrophic organisms while fungi are heterotrophic organisms.
- Plants have vascular tissue, and fungi don't.
- Fungi are the only organisms that have cell walls made of chitin.
Therefore, the correct choice is that both fungi and plants can grow in soil.</span>
Answer:
Some of the energy is used by decomposers, and some of the energy is released into the environment as heat.
The producer intakes energy from the sun and 10 % of energy is passed on to tropic level I, and similarly at each tropic level 10% of the energy is passed on and the decomposer are at the last tropic level. Thus they also receive 10% of energy and rest all is released into the energy.
Explanation:
