Notice that the by-products of one process are used as the reactants for the other process. This is referred to as the of molecules.

cycling of molecules

Explanation:

In a cell, the flux of energy is associated to the cycling of molecules among subcellular compartments. In coupled reactions, the cycling of molecules between mitochondria and chloroplasts is required to produce the flow of energy and to sustain the life of the Earth. Chloroplasts produce chemical energy by using solar energy to convert water and carbon dioxide (CO2) into oxygen (O2) and high energy carbohydrates (i.e., sugars and starches). Subsequently, in the mitochondria, the process of cellular respiration enables to convert the carbohydrates into high energy molecules (ATP), releasing water and CO2.

americans began to notice growing differences between the northern and southern sections of the country. there were more people living in cities in the north, which made it more urban. more people lived on farms in the south, which made it more rural. while many people were farmers in the northern states, there were now other ways to make a living, such as working in mechanical cotton gins factories manufacturing cloth, tools and other goods. people in the north supported high tariffs on goods imported from europe because the extra cost encouraged people to “buy american” instead. in the southern states, planters did not like tariffs because they sold most of their production to europe and bought their tools from there as well. southerners believed the protective tariff was something that only northern factory owners keep their profits high. so the southern politicians came up with an idea. they would opt out. they would simply ignore the protective tariff. it was ‘null and void’ in south carolina. the state would not collect the taxes on goods imported into south carolina, no matter what the president said they had to do. this decision led to the nullification crisis.

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands