<span>Since muscle contraction depends on interactions between actin, myosion and some intermediate molecules, the primary protein structure of such proteins and their spatial conformation are fundamental for their functioning. For example, actin and myosin, both filamentous proteins that slide past each other or troponin/tropomyosin interactions that blocks the binding of myosin to actin.</span>
A specific type of physical change is a phase change
Answer:
Farmers have been using selective breeding for improving their crop qualities and producing animals with better characteristics.
improved so that mankind can benefit from it.
Selective breeding is not okay on a bigger level where it might eradicate the natural varieties of plants and animals completely. When done on a larger level, the wild-type traits of plants and animals will change and be removed completely. This will lead to lesser genetic diversity.
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.
Sickle cell disease has a benefit in malaria infection because it makes the parasites easier to eliminate. This makes a person with sickle cell disease is more likely to survive the malaria infection, which found many in Africa.
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Sickle cell disease has a few drawbacks because it makes the red blood cells less durable, which lead to the destruction of more red blood cells. In normal condition(where malaria doesn't exist like in America), this gene will make the organism less likely to survive than those who don't have the gene.</span>
