<u>Answer: </u>
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Lipids
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Explanation:
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Lipids are the macro-molecules used to store energy in our body. They have the ability to store energy more efficiently and are called long-term energy storage.
They can store twice as much energy as other molecules. They contain nine Kcal of energy per gram a compared to proteins and carbohydrates which only produce four kcal per gram. They are present in our body in the form of fat and are insoluble in water.
The sled with a rough metal bottom would take more force to move over ice, because the rough surface would increase friction and the force needed.
The order of flow of oxygen within the human body may be described simply. Oxygen first is inhaled through the nasal cavity and then passes through the trachea, through the bronchi and into the lungs. In the lungs, the oxygen is passed into the blood stream through the alveoli and then is carried to the heart. The heart pumps this oxygenated blood throughout the body, primarily to organs and muscle cells, where it is consumed in respiration and is converted to carbon dioxide and excreted.
