CHAPTER 2b SCIENCE F5 KSSM

Formative Practice 2.2

Page 61 Science Form 5 KSSM Text Book







Nitrogen Cycle

Prepared by: Pn. Nurulkamilah binti Khairir

Student is able to: 2.3 Nitrogen Cycle

 Communicate about

the nitrogen cycle and

its importance

Nitrogen Cycle

Nitrogen cycle is a natural cycle that
recycles nitrogen between plants and animals,

and the atmosphere, soil and water.

78% of air is made up of nitrogen

How do plants obtain nitrogen since plants
cannot absorb nitrogen directly from air?





Processes that Add

Nitrate ions to the soil

Lightning and Volcanic Eruption

Heat energy released at high temperatures
oxidises nitrogen in the air to form nitrogen

dioxide

Nitrogen dioxide dissolves in rainwater to form
nitric acid

Nitric acid seeps into the ground and react
with minerals to form nitrate ions





Nitrogen Fixation

Nitrogen-fixing bacteria in the soil, water or
living symbiotically in legume plant root nodules

Convert nitrogen in air into nitrate ions



Nitrification

01 02 03 04 05

Animals and Decomposing Nitrifying Nitrate ions Plants can
plant die bacteria bacteria convert increased in the absorb the
convert animal ammonium soil nitrate ions
and plant compounds
proteins into into nitrite ions
ammonium then nitrate
compound ions



Processes that Extract

Nitrate ions from the soil

Absorption of nitrate ion

Plants absorb nitrate ions from the soil and use nitrates to form plant
protein. Animal eat plants and animal protein is formed

Denitrification

Denitrifying bacteria convert nitrate ions in the soil into nitrogen

Nitrate leaching

Nitrate ions in the soil dissolve in water and flow into rivers or
underground water

Importance of Nitrogen Cycle

Maintaining a continuous Reducing environmental
supply of plant and pollution
animal proteins

Maintaining nitrogen Maintaining Nitrogen is an important The remains of dead animals
content in air fertility of soil component in the formation of and plants undergo decay
protein. Protein is used to and decomposition to form
The nitrogen cycle helps to The removal of nitrate ions build new cells and repair ammonium compounds and
maintain the nitrogen content reduces the fertility of the soil. damaged cells. then nitrate ions through
in the atmosphere by The problem of infertile soil A continuous supply of protein bacterial and fungal actions.
removing nitrogen from the air can be solved through is important to ensure the Processes in the nitrogen
to form nitrate ions and crop rotation and use of continuity and maintenance cycle such as nitrification
returning it to the air by fertilisers to increase the of life for all types of living help to reduce
decomposing nitrate ions. content of nitrate ions in the things. environmental pollution
Therefore, the concentration soil again. Plants use nitrogen from the and are applied in green
of nitrogen is maintained at As a result, plants become nitrate ions that are absorbed technology to produce
78% in the atmosphere to healthier. The productivity of to form plant proteins. Animals compost
help ensure the continuity and crops rises and the income obtain nitrogen by feeding on
sustainability of life on Earth of farmers increases. plants or other animals

Formative Practice 2.3

Page 65 Science Form 5 KSSM Text Book







Food Production
Technology

Prepared by: Pn. Nurulkamilah binti Khairir

Student is able to: 2.4 Food Production
Technology
 Communicate about
the nitrogen cycle and
its importance

 Evaluate the use of
pesticides and biological
controls to increase the
quality of food production

FOOD PRODUCTION TECHNOLOGY

to solve problem

of global food shortage

The measures used in food production
technology include

• Increasing food quality.
• Increasing the food quantity of food
production

• Producing and using quality breeds

• Using various types of modern technology



1



2







3

https://www.mafi.gov.my/alamat-jabatan-dan- http://buku-
agensi teks.com/sc5070
https://www.mardi.gov.my/

http://www.mpob.gov.my/

4

5



6



Elimination

of crop pests



Pesticides such as insecticides are easily
used to control the population of crop pests

Using this method has side effects

Polluting the environment, increasing
pesticide resistance of crop pests, killing
earthworms and useful microorganisms
and contaminating the land and crop yield