Striated muscles contain repeating sarcomeres of overlapping arrays of long, thin actin and thicker myosin filaments. Myosin filaments contains the myosin heads, which are enzymes that can bind to actin, split and make use of the energy from ATP. When muscle contraction starts, myosin heads bind to actin, change their configuration on actin, liberating the products of ATP hydrolysis and causing slide of the actin and myosin filaments. The action of the proteins troponin and tropomyosin on the actin filaments regulates vertebrae striated muscle contraction. The release of calcium ions from the sarcoplasmic reticulum is triggered by the nervous stimulation which causes depolarization of muscle membrane. Calcium ions bind to troponin and thus cause or allow the tropomyosin strands on the actin filament to move so that the part of the actin surface where myosin heads need to bind is uncovered. Contraction then occurs and only stops when the sarcoplasmic reticulum pumps calcium out of the muscle interior.
So basically, what triggers the uncovering of the myosin binding site on actin is the calcium ions binding to troponin and changing configuration.
Explanation:
seals more offspring when food is plentiful
Answer:
Gene therapy is the process or replacing mutated genes with normal genes in an attempt to heal diseases by correcting the functional code of the gene. Mutated genes can cause genetic disorders. Transformation and transfection are the two methods used to insert a normal gene into an organism. The process of transformation occurs in a laboratory. Cells are grown in the lab and then introduced to DNA that carries the gene of interest. Transfection uses a virus to introduce the gene of interest to the host cells.
Gene therapy is a relatively new biotechnology. It is very expensive and much more research needs to be done before it is perfected. Gene therapy has had the best results in the treatment of cancer. One of the ways gene therapy is used in cancer treatment is by inserting a gene that is more sensitive to treatments such as chemotherapy and radiation.tion:
<span>Even though Seattle is located
near the mountains like Denver, it is also a coastal city. The Pacific Ocean helps
moderate the climate in the area. I believe certain currents nearby also give
the Pacific Northwest area a somewhat subtropical climate.</span>
