2007-09-22 10:11:14 · 4 answers · asked by amcheung10 2 in Science & Mathematics ➔ Biology
Yes, all life is made primarily of water, which are molecules of 2 hydrogen atoms bonded with one oxygen atom. Water is an excellent liquid within which chemical reactions can occur, reactions that are necessary for life.
But oxygen alone is also essential for all complex animal life. Oxygen is the only element which can produce a great deal of energy, sufficient for multicellular life to move around. Oxygen produces such high energy by being able to "burn" sugar. There is no other way we know that high energy can be produced in a living organism. So scientists speculate that complex animal life can only evolve on a planet that has an atmosphere rich in oxygen.
2007-09-22 10:51:15 · answer #1 · answered by Dendronbat Crocoduck 6 · 0⤊ 0⤋
In addition to the oxygen and hydrogen in the water molecules of an organism, the main organic compounds all contain oxygen and hydrogen.
carbohydrates have C, H, O
lipids have C, H, O
proteins have C, H, O, N, S
nucleic acids have C, H, O, N, P
2007-09-22 11:46:09 · answer #2 · answered by ecolink 7 · 0⤊ 0⤋
Hydrogen Bonds, Water, Cellular Respiration
2007-09-22 11:30:38 · answer #3 · answered by babbinator1227 2 · 0⤊ 0⤋
Because they do. Humans alone have 60% water--at least.
2007-09-22 10:20:31 · answer #4 · answered by ~*Natasha*~ 3 · 0⤊ 0⤋