Homeostasis is a self-regulating technique by which systems
in the body maintain stability and tend to adjust to optimal conditions which
are essential for survival. Thereby, the role of homeostasis is to help the
body maintain constant internal environment. A good example of homeostasis
would be ‘drinking excess alcohol causes vomiting’.
Malic acid and I need points
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:
The correct answer is - domain.
Explanation:
In a taxonomic system, all the organisms fall into three broad groups that comprise different kingdoms of the organisms. This group of taxa known as Domain and it is the broadest and most inclusive taxa of the taxonomic system. It includes three groups Archaea, bacteria and eukarya.
Archaea and bacteria were used to comprise in one group but due their differences archaea are divided into new group. These domains have all the organisms present on earth.
