Nutrients like carbohydrates, fats, proteins, vitamins, and minerals provide living organisms with the materials needed to build their bodies, grow, repair damage, and power life processes. Nitrogen is essential for organisms but it exists primarily as unusable atmospheric N2; biological fixation by rhizobium bacteria in legume roots and other soil microbes, as well as atmospheric fixation from lightning, make nitrogen biologically available for use by plants and animals.

1. Nutrition in living organisms
SCIENCE
3/08/2021 7th

2. Nutrients :- The components of food like
carbohydrates, fats, proteins vitamins and
minerals are called nutrients.
Nutrients help living organisms :-
i) To build their bodies.
ii) To grow.
iii) To repair the damaged parts of
their bodies.
iv) To provide energy to carry out life
processes.

4. Xylem
Phloem

5. Chocolate
Coco beans

6. Raw potato
Cooked potato

7. Spinach
Palak paneer

8. Carbohydrates Proteins
C O
H
N
O
H
C

11. Roots are responsible
for water and
minerals
absorption

12.  Nitrogen (N2) is an essential component of DNA, RNA, and
amino acids. All organisms require nitrogen to live and
Majority of the air we breath is N2. (78%) Most of the
nitrogen in the atmosphere is unavailable for use by
organisms.
 In order for plants and animals to be able to use nitrogen,
gas must first be converted to more a chemically available
form. Biologically available nitrogen is usually short of
in natural ecosystems, limiting plant growth and biomass
accumulation.

14. Nitrogen
fixation
Biological Atmospheric

15.  Air contains gaseous nitrogen.
 However, plants cannot utilize
gaseous nitrogen.
 It needs to be fixed i.e. converted
into compounds. This process is
called as Nitrogen Fixation.
 Fixation of nitrogen occurs by
biological and atmospheric
methods.

16.  Two different types of micro-organisms can
bring about biological nitrogen fixation.
Root-nodules of leguminous plants contain
the rhizobium micro organisms. These
micro-organisms absorb atmospheric
nitrogen and convert it into its nitrate, a
compound.
 Micro-organisms like azotobacter are
present in soil. They also convert
atmospheric nitrogen into nitrates.

21.  Lightning (thunderbolts) occur in the rainy season. This
causes atmospheric nitrogen and oxygen to react with
each other to form nitric oxide (NO) which is again
oxidized to form nitrogen dioxide (NO2).
 The nitrogen dioxide dissolves in rainwater and is
converted into nitric acid (HNO3)
which gets added to the soil
along with the rain-water. Plants
use this nitrogen for their growth.

23.  Bacteria play many roles in our ecosystem. Bacteria
are decomposers which break down dead material and
recycle it. They also can be producers, making food
from sunlight, such as photosynthetic bacteria, or
chemicals, such as chemosynthetic bacteria.
 The beneficial uses of bacteria include the production
of traditional foods such as yogurt, cheese, and
vinegar.

24.  Nitrogen : Nitrogen (N2) is an essential component of DNA, RNA, and
amino acids. All organisms require nitrogen to live and grow.
 Biological fixation of nitrogen: Two different types of micro-organisms
can bring about biological nitrogen fixation. Root-nodules of
leguminous plants contain the rhizobium micro organisms. These micro-
organisms absorb atmospheric nitrogen and convert it into its nitrate, a
compound.
 Atmospheric fixation of nitrogen: Lightning (thunderbolts) occur in
the rainy season. This causes atmospheric nitrogen and oxygen to
react with each other to form nitric oxide (NO) which is again
oxidized to form nitrogen dioxide (NO2).
The nitrogen dioxide dissolves in rainwater and is converted into
nitric acid (HNO3).

25. Which micro-organisms absorb atmospheric nitrogen
and convert it into its nitrate?
Rhizobium Lactose

26. Ammonia is converted into nitrite this process is called
as ________
Nitrifying Denitrifying

27. Molecular formula of ammonia is ________
NH3
NH2

29. Thank You!