The method of virus transmission which results in a greater spread of disease is through airborne transmission
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:
As the outer layer of your skin separates your body from its environment, the cell membrane (also known as the plasma membrane) separates the inner contents of a cell from its exterior environment. This cell membrane provides a protective barrier around the cell and regulates which materials can pass in or out.
Explanation:
Answer:
B
Explanation:
The net movements of water from the region of higher water potential to the region of low water potential through a selectively permeable membrane is osmosis. It is a form of diffusion which involves the transport of water molecules.
In this present scenario water molecules pass through the selectively permeable membrane from higher water potential in the body, to lower water potential but high solute potential (Epsom salts). The later is called an hypertonic solution,this is because it has higher solute potential ,thus higher salt concentration than the surrounding medium,therefore water pass by osmosis into the Epsom salts.
If one is placed in this solution,the cells shrink as they lose water to the more concentrated Epsom.(hypertonic solution)
However, the body homeostatic mechanism through the kidney ensure re-absorption of fluid back to the body from the DCT and CT, via anti diuretic hormone to preserve the cell and the person.
