Muscle cells need a specific form of energy for contraction and cannot use the energy released directly from breaking down glucose or triglycerides. Rather, body cells must first convert food to adenosine triphosphate (ATP). <br /><br /> Food is digested and processed into ATP through sever different stages.
Answer:
Blood Brain Barrier(BBB)
Explanation:
This is a biological interface of special endothelial cells of astrocytes, pericytes , capillaries, neurons and other structures, acting as a physical barrier or gate separating the Central Nervous system from the peripheral blood circulations. Thus it formed a tight junction serving as a physical barrier to selectively regulate the entrance of substances from the cerebral blood flow into the brain, therefore maintaining homeostasis of the brain.
From above any substances absorbed into the blood stream irrespective of the mode of entry are transported through the BBB, and are selectively regulated to enter the brain cells by the BBB's interactions with the blood vessels, hormones etc.
Basically it allows the passage of nutrients, a few drug, hormones and resists certain toxins and pathogens for the brain homeostasis.
The phospholipid molecule is both hydrophilic and hydrophobic which allows it to organize into a bilayer with the hydrophobic tales tucked away and the hydrophilic head exterior. This bilayer is also semipermeable allowing some small molecules in for the cell to use
Answer:
The North American fur trade was an industry and activity related to the acquisition, trade, exchange, and sale of animal furs in North America. Aboriginal peoples in Canada and Native Americans in the United States of various regions traded among themselves in the pre–Columbian Era. Europeans participated in the trade from the time of their arrival in the New World, extending the trade's reach to Europe. The French started trading in the 16th century, the English established trading posts on Hudson Bay in present-day Canada during the 17th century, while the Dutch had trade by the same time in New Netherland. North American fur trade was at its peak of economic importance in the 19th century, and involved the development of elaborate trade networks.
The fur trade became one of the main economic ventures in North America attracting competition among the French, British, Dutch, Spanish, and Russians. Indeed, in the early history of the United States, capitalizing on this trade, and removing the British stranglehold over it, was seen as a major economic objective. Many Native American societies across the continent came to depend on the fur trade as their primary source of income. By the mid-1800s changing fashions in Europe brought about a collapse in fur prices. The American Fur Company and some other companies failed. Many Native communities were plunged into long-term poverty and consequently lost much of the political influence they once had.
Explanation:
