Answer:
the small intestine moves water from your bloodstream into your GI track to help break down to help break down food. The small intestine also absorbs nutrients. in the large intestine more water moves from your GI tract into your bloodstream
Answer:
The myosin filament or more precisely the myosin head can now bind to the actin forming the cross bridges followed by a power stroke during which actin slides over myosin.
Explanation:
The muscle contraction can be explained by sliding filament theory bu Huxley and Huxley. The two muscle proteins which take part in muscle contraction are myosin and actin.
Myosin: It is a hexameric protein. Each monomer is called meromyosin. Each meromyosin has two important parts, a globular head with a short arm and a tail. The head forms cross bridges with the actin filament. Myosin head acts as ATPase enzyme. When ATP binds, head acts as enzyme hydrolyzing the ATP to produce energy. The head also has the site for binding of actin.
Actin filament: It contains three proteins, filamentous actin, tropomyosin and troponin. Filamentous actin contains active site for myosin binding but at rest, tropmyosin covers the myosin binding site. This prevents the cross bridge formation. Tropomyosin are held in place by troponin molecules.
When calcium is available, the binding of calcium to a TpC sub-unit of troponin causes the shifting of tropomyosin-troponin complex. Now actin can attach to myosin head and slide over myosin.
The actin filaments slide over the myosin filament by the the formation of cross bridges and during this process the I-band gets reduced whereas the A band remain the same. The lengths of actin and myosin filaments remain unchanged.
Snail:
• They have a shell that is adapted to protect them against predators and the elements.
• They are also adapted to hibernate, especially snails that live in areas prone to frost or freezing temperatures, during the winters. Alternatively, snails in dry, arid regions will estivate - a summer version of hibernation - when water is scare or when there are droughts.
• Snails' slime is naturally hygroscopic, meaning that, instead of releasing water, it attracts it. This helps snails stay damp throughout the day and assists in movement, reproduction and breathing.
Crabs:
• Instead of having an internal skeleton they have exoskeletons. This creates an extremely hard exterior making them more susceptible to attacks from predators.
• All crabs have eight regular legs and two specially adapted legs known as chelipeds or claws. They help them to feed and to catch prey.
• All crabs have both a set of antennae and antennules. They see through their eyes, which are located on the end of long eyestalks. The purpose of these eyestalks is to allow them a better field of vision -- they can see in front of themselves, behind themselves and to the sides -- which is an advantage when hunting or looking out for danger.
The answer is <span>D. a day with an equal amount of daylight and darkness
altho truly it would be a day that there is 12 hours exactly between sunup and sundown because there is light for more than just the 12 hours </span>in between<span />
