Plants and algae make food via
sunlight energy and photosynthesis and this increases their biomass -
which is an important source of food and energy for animals.
Almost all life on Earth
depends on photosynthesis in plants and algae at the base of
most food chains.
This also means that most chemical potential energy
for life is indirectly derived from the Sun, which is used to make a
range of organic molecules from complex carbohydrates, sugars,
proteins and lipids (fats and oils).
The carbohydrates store chemical potential energy
from photosynthesis, which is passed down a food chain from
plants/algae to animals when animas eat these photosynthesising
organisms.
Only plants, algae like seaweed or phytoplankton and
some bacteria can carry out photosynthesis.
Carbon dioxide is slightly soluble in water (as
is oxygen) so aquatic organisms in water can carry out
photosynthesis near the surface.
Fortunately for animals, photosynthesis in
plants keep the oxygen level at around 20% in the Earth's
atmosphere and respiration by animals keeps the carbon dioxide
level at around 0.04%, which is sufficient for plants to thrive.
For more details see
the
Carbon cycle
The importance of photosynthesis
You should appreciate the dependence of almost all life on Earth on the
ability of photosynthetic organisms, such as plants and algae, to
use sunlight in photosynthesis to build organic molecules that are
an essential energy store and provide chemical energy for all
cellular chemistry from respiration to protein synthesis, and to maintain levels of oxygen and
carbon dioxide in the atmosphere
Green plants and algae are producers based on
the chemistry of photosynthesis and the start of most food chains and
the base of subsequent food webs.
Generally speaking, plants and algae do NOT eat
food, but produce it.
(There are plants that trap insects for food,
BUT, they are still use photosynthesis too.)
We are highly dependant on crops whether to eat directly,
processed food or animal feed - so, we might not be 'green', but we ultimately
depend for a lot of our food on photosynthesis!
AND, its not just life on land,
all aquatic life e.g. fish, also depend, initially, on photosynthesis in plankton or algae.
A food chain is a means of transferring the energy from
photosynthesis in the biomass to support many forms of life, including us!
Even the meat we
eat, high in protein and fat, did depend at some point on photosynthesis, so there is no getting away from photosynthesis!
INDEX of all my BIOLOGY NOTES
This is a BIG website, so try using the [SEARCH
BOX], it maybe quicker than the many indexes!
email doc
brown - comments - query?
UK KS3 Science Quizzes for
KS3 science students aged ~11-14, ~US grades 6, 7 and 8
Biology * Chemistry
* Physics UK
GCSE/IGCSE students age ~14-16, ~US grades 9-10
Advanced Level Chemistry
for pre-university ~16-18 ~US grades 11-12, K12 Honors
Find your GCSE/IGCSE
science course for more help links to all science revision notes
Use your
mobile phone or ipad etc. in 'landscape' mode?
