2. Nutrition and types of nutrients
✧ The process of taking in and using food, which takes place
in living organisms is called nutrition
✧ We get several types of nutrients from foodstuffs .
Nutrients can be classified into two types macro nutrients
and micro nutrients
✧ Nutrients like carbohydrates ,proteins ,fats are required in
large quantity these are called macro nutrients
✧ Minerals like vitamins , minerals are required in small
quantity they are called micro nutrients
3. What is the need for nutrition
✧ The needs for nutrition in living organisms are:
✧ To supply the energy required for doing work.
✧ Growth and development of the body.
✧ To replace the damaged cells and repair tissues.
✧ To fight diseases.
4. Explain the Types of nutrition
✧ Autotrophic nutrition-Some organisms can
produce their own food and thus nourish
themselves This is called autotrophic nutrition
✧ Heterotrophic nutrition-Some organisms depend
on other organisms ,plants or animals, for their
food. This is called heterotrophic nutrition,
5. Types of Nutrition in plants
✧ Autotrophic-Process of nutrition in which organisms can
synthesize their own food and thus nourish themselves.
✧ Heterotrophic –Some organisms depend on other
organisms , plants or animals, for their food .This is called
heterotrophic nutrition.
✧ Symbiotic –In some cases ,two or more than two different
types of plant live together to fulfill their needs for nutrition
, protection , support etc . with each others ‘ help . This
type of nutrition is called symbiotic nutrition.
6. Autotrophic plants
✧ Plants can produce their own food .With the help of
sunlight and chlorophyll, plants make their food in their
leaves, using water and nutrients from the soil and carbon
di-oxide from the air .This process is called as
photosynthesis.
8. Autotrophic plants
✧ Plants convert light energy into chemical energy and store
it in the form of food.
✧ Water , minerals and salts are absorbed by roots from the
soil. The stem transport them up to the leaves. The leaves
have microscopic openings called stomata through which
they take co2 from the air. The chloroplasts present in the
leaves contain chlorophyll , which absorbs sunlight ,
helping to convert carbon dioxide and water into food .
Oxygen is given out in this process.
10. Transport system in plants
✧ The transport system in plants consists of the xylem and
phloem.
✧ The xylem transports minerals and water from the root to
all aerial parts of the plants
✧ The phloem transport the food ( glucose ) from the leaves
to other parts of the plants where it is either consumed or
stored.
11. What is chemosynthesis
✧ Chemosynthesis is the biological conversion of
one or more carbon containing molecules and
nutrients into organic matter.
It uses the oxidation of inorganic compounds or
methane as a source of energy rather than
sunlight.
Sulphurbacteria and nitrosomonousproduce their
food by chemosynthesis.
12. Biological Nitrogen Fixation
✧
Biological Nitrogen Fixation. ...Biological nitrogen
fixation (BNF), discovered by (Beijerinck1901), is
carried out by a specialized group of
prokaryotes. These organisms utilize the enzyme
nitrogenaseto catalyze the conversion of
atmosphericnitrogen(N2) to ammonia (NH3).
13. Nitrogen fixation
✧Nitrogen fixation is a process by which
molecular nitrogen in the air is converted
into ammonia or related nitrogenous
compounds in soil. Atmospheric nitrogen
is molecular dinitrogen, a relatively
nonreactive molecule that is metabolically
useless to all but a few microorganisms.
Eg: rhizobium, azotobacter.
14. 2.Atmospheric fixation of nitrogen
✧ Lightning occurs 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 which gets added to the soil
along with rain-water . This acid reacts with different
minerals in the soil and converted into salts . Plants use
this nitrogen salt for their growth.
