Do you mean electron? If so they are molecules that transport electrons during cellular respiration.
Blood moves very slowly through capillaries. As the blood moves through a capillary, nutrients, oxygen, and food leave the blood and enter the body cells. ... Capillaries are exchange vessels. Gases (oxygen and carbon dioxide), nutrients, and wastes pass in both directions across capillary walls.
Answer:
Carbon dioxide is added to the atmosphere naturally when organisms respire or decompose (decay), carbonate rocks are weathered, forest fires occur, and volcanoes erupt. Carbon dioxide is also added to the atmosphere through human activities, such as the burning of fossil fuels and forests and the production of cement.
Explanation:
Sedimentary rocks are formed because of overburden pressure
#3 food is absorbed through cell menbranes(i think