Transcription is the process in which mRNA is produced from DNA by using transcriptase enzyme.it involves the following process:splicing,5 END methylation cup,3 end polytail A .
Fungi are decomposers, they obtain their food from dead organic matters. Fungi obtain their nutrient this way because they can not produce their own food. To produce their own food they need chloroplast in their cells to obtain energy from the sun. And they also need the ability to fix nitrogen which they will incorporate into the food they produce. Because they lack the ability to do this thing, they have to adapt to eating dead materials. <span />
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.
Its like 2 twizzlers twisted to the left with marshmellows attached.