Insects, such as water striders, and spiders, such as fisher spiders, can glide or scamper across the surface of water. These critters are small enough that their weight can be supported almost entirely by surface tension, the relatively weak forces that hold water molecules together.
Surface tension of water helps creatures(mostly of insecta class such as water striders) to walk on water. ... it also helps water to move up the xylem tissue of higher plants without breaking up
They have evolved into the best length for their environment.
Answer:
1. Inhibiting IP3 channels, leading to decreased Ca2 in the sarcoplasm and reduced contraction.
2. Increasing the relative activity of MLCP, leading to a decrease in tension.
3. Activating K channels, increasing K leaking out of the cell which hyperpolarizes it and decreases the likelihood of Ca2 entry.
Explanation
In smooth muscle, cyclic AMP (cAMP) mediates relaxation because cAMP inhibits a specific kinase required for myosin light chain protein (MLCP) phosphorylation, thereby triggering contraction in the smooth muscles. It has been shown that cAMP inhibits 1,4,5-trisphosphate (IP3)-dependent calcium ions (Ca 2+) release by activation of the cGMP-dependent protein kinase (PKG). PKG proteins act to modulate Ca2+ oscillations by stimulating sarcoplasmic Ca2+-ATPase membrane proteins, increasing Ca2+ in the sarcoplasmic reticulum stores and Ca2+ efflux from the cells, and activate voltage-gated potassium (K) channels, thereby leading to membrane hyperpolarization and reducing Ca2+ entry through Ca2+ channels.
