| Where do we get our supply of oxygen?|
|Question Date: 2018-07-24|
The oxygen we breathe comes from a lot of
different places. The largest source of oxygen
comes from organisms (living things) that can
perform photosynthesis, which is a word that
describes the process in which a living thing uses
sunlight, carbon dioxide and water to make
sugars and oxygen. After sugars and oxygen are
produced, the organism uses the sugars as energy,
and sends the oxygen out as a "waste"
product. There are many things that perform
photosynthesis, especially plants and organisms in
the ocean. As to the source of the carbon
dioxide, it can come from humans when we burn
fossil fuels (gasoline and so on); carbon
dioxide can also be released into the atmosphere
by volcanoes and from rocks that have carbon.
Together, the amount of carbon dioxide in the
atmosphere and the number of organisms that can
perform photosynthesis play very important roles
in the amount of oxygen available in our
atmosphere for breathing and other processes (such
as lighting a fire).
The oxygen (O2) of Earth is primarily a
of photosynthesis. Photosynthesis is the process
performed by plants and plant-like organisms like
phytoplankton which converts sunlight and
food. To these organisms, the O2 is a waste
product that is released. Although land-based
plants, such as rain forests, are the focus of
highly-publicized conservation efforts, the
in the ocean contribute far more
O2; up to
85% of the oxygen in our atmosphere comes from
these ocean-dwellers. (Delving a bit deeper, the
photosynthesizing part of these organisms is the
chloroplast. Chloroplasts are thought to be the
descendants of an ancient cyanobacterium.
It was cyanobacteria which first began producing
oxygen, billions of years ago. The
plants developed after cyanobacteria formed
symbiotic (mutually beneficial) relationships with
early eukaryotic cell which engulfed
Plants, algae, and some bacteria make sugars out
of carbon dioxide, water, and light. In the
process of making these sugars, they produce
oxygen as a byproduct. This is where all of our
oxygen comes from.
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