Melatonin (<span>also known as N-acetyl-5-methoxy tryptamine)</span>
Answer:
So they are lighter and move quicker.
Explanation:
With the small wings and bodies birds have it would be hard for them to escape predators and lift their own weights if their bones were dense like humans' bones. The hollow part of the birds' bone is connected to their lungs so they have enough oxygen to fly easily. Hope this can help you! :)
A molecule that moves across a cell membrane without using the cells energy tend to move C IS THE ANSWER
C-nucleic acid is a component of deoxyribonucleic acid which is the provides the cell with its genetic makeup as well as its genetic blueprint.
The correct answer is C. troponin only.
The smooth muscle cells contain similar elements like the cardiac and skeletal muscle cells including actin, myosin and tropomyosin but they contain troponin.
Smooth muscle tissues are non striated and produce their own connective tissue called endomysium. Smooth muscle cells also lack sarcomeres but have other thin and thick filaments along with actin and myosin contractile proteins.
Due to lack of troponin the cross bridge formation is regulated by the regulatory protein calmodulin instead of the troponin- tropomyosin complex.