LIFE PROCESS
Note:- These steps need not take place one after the other immediately.
Fig:-Crossectional view of a leaf.
Ø The basic functions performed by living
organisms in order to maintain their life on the earth is called life process.
For example :- Nutrition, Excreation, Respiration, Movement, Control
& Co-ordination, Reproduction etc.
NUTRITION
1. It
is the way of getting or obtaining food by the organism.
2. It is important to grow, develop, synthesise
protein and other substance needed in our body.
There are two types of Nutrition:-
1. Auto tropic Nutrition:- The Nutrition
in which organism make their own simple food materials obtained from inorganic
sources in the form of carbon dioxide, water and some other compounds.
For example:- Nutrition in plants and some
bacteria.
NUTRITION IN PLANTS
In plants, Nutrition
takes place by the process of photosynthesis.
PHOTOSYNTHESIS:- It is an process in which green plants
manufacture carbohydrate from inorganic molecules like Co2 and H2O
in the presence of sunlight.
6CO2+12H2OC6H12O6+2H2O+6O2
Event that occur during the process of Photosynthesis are:-
1. Absorption of light energy by chlorophyll.
2. Conversion of light energy to chemical
energy and splitting of water molecules into hydrogen and oxygen.
3. Reduction of carbondioxide to
carbohydrates.
Note:- These steps need not take place one after the other immediately.
For example :- In carbondioxide
is taken at night and prepare an intermidiate which is acted upon by the energy
absorbed by the chlorophyll during the day.
Ø Chlorophyll :- Most important pigment
which traps solar energy and convert into chemical energy.
Ø Basically it is of seven types:-
· Chlorophyll A to E
· Chlorophyll A to E
· Bacteriophyll
· Bacterial Vidin
--->Cholorophyll A is responsible for the transformation of solar energy into chemical.
--->Cholorophyll A is responsible for the transformation of solar energy into chemical.
Ø Remain types absorbs solar energy and
gives to chlorophyll A.
Formulla of chlorophyll
A--
C55 H12
O N4 Mg5
Ø Due to the persence of Mg, leaves of
plant look like green.
Ø Other pigments of plants are
· Xanthrophyll -- Yellow
· Carotence (carotenoides)-- Red
Ø In leaves, photosynthesis occures in
measophyll area.
Fig:-Crossectional view of a leaf.
Mechanism of Photosynthesis
1. Opening and closing of Stomata
2. Exchange of gases
Stomata :- These are
the tiny pores present on the surface of leaves.
In nerbaceous plants,
stomata are also present on the steam.
Each stoma (pl.stomata)
is surrounded by two guard cells contains cholorophyllast and Nucleous.
1. Opening and closing of stomata opening of
Stomata:- Stomata opens during day time towards
inwards directions.
2. In day time enough glucose formed through
photosynthesis is converted into starch which is insoluble. So, the guard cells absorbs excess water from
surrounding cells and became turgid.
3. Due to turgidity of gardcells, stomata
opens.
CLOSING OF STOMATA
1. Stomata remains close at night.
2. At night when no photosynthesis occurs
the starch is converted into Glucose.
3. Due to which the osmotic concertration
increases resulting exoosmosis of guard cells.
4. This leds to shrinkage of guard cells and
stomata gets closed.
Note:- Stomata remains
close during day time also when atmospheric temperature exceeds more that 350
to 400 c. At night
minute stomata pore remains opens for respiration.
Exchange of gases:- The
gases exchange in plants takes place through stomata by the process of
diffusion.
The net exchange of gas
during day time is co 2 to o2
and during night is o2 to co2.
Bacterial Nutrition
or,
Chemosynthesis
or,
Bacterial
photosynthesis
It is a process which
occur. In bacterial cells. In this process certain bacteria like
chlorobium, sulphur bacteria etc .
Manufacture carbohydrate in the persence of sunlight from co2
& other chemical instead of water.
In chemosynthesis No,
oxygen gas is rebased as by produced.
6co2+12H2S
:--> C6H12O6+I2S +12H20
Heterotropic Nutrition
The nutrition in which
organism obtain their food from autotrops or any other organism,
They may be
saprophytes, symbiotic, sapozoic, or parasitic or Holozoic.
Paracytism:- It is a type of nutrition in which any
organism get their food from other hosts are called paracytism.
Saprophytic Nutrition
:- In this type of nutrition the plants
obtain food from dead and decaying organic matter.
eg:- Aspergillus,
Mushroom etc.
Symbiotic Nutrition :-
A neterotropic mode of nutrition in which two different organism like together
closely for getting mutual benefit called symbiotic.
Holozolic
Nutrition :- The mode of nutrition in
which organism take solid food is called
holozoic nutrition.
eg:- Amoeba, Human
beings, all the animals etc.
Phases of Holozoic
Nutrition
Holozoic nutrition
completes into 5 steps-
1. Ingestion :- Intake of food in mouth.
2. Digestion :- Breaking down of complex
food molecule into simple and soluble forms by the action of various enzymes is
called digestion. It is a Catabolic
process.
Note :- Enzyme are
bio-catalystist used by organism for breaking of complex substance into simple
ones.
Absorption :- It is the
process in which digested food molecules are absorbed.
Assimilation :- The
utilization of absorbed food molecules to recognised the complex. organic molecules is called absorbtion.
It is an annobolic
process.
Egestion :- The removal
of undigested food and unabsorbed food out from body in the form of stool or
faeces also called egestion.
Nutrition in Amoeba
Amoeba
takes in food using temporary finger like extension of the cell surface which
fuse over food particle forming a food vacuole.
Inside
the food vacoule, complex substance are broken down into simpler ones which
then diffuse into cytoplasm. The
remaining undigested food material is moved to the surface of cell and thrown
out. In paramecium which is also a unicallar organism the cell has a difnite
shape and food is taken in at a specific spot.
Food is moved to this spot by the movement of cilia which cover the
entire surface of the cell.
Nutrition
In Human Beings
1. Igestion :- In this step, food is taken
into the mouth.
2. Digestion :- A catabolic process in which
complex food molecules are broken down into simple soluble form by the action
of various digestive enzyme is called Digestion.
In
human extracellular digestion takes place.
Site
of Digestion :-
1. Buccal digestion :- In the mouth just
after ingestion. In mouth physical and
chemical digestion takes place.
· Physical digestion :- Refers to
mestication (changing) of food.
· Chemical digestion :- Occures during
mestication when chewed food mixed with salvia where staren is converted into
sugar through salivary amylase.
About
30% of digestive takes place into mouth.
After
buccal digestion, food goes to stomach for gastric digestion by the process of
peristalsis through oesophagus.
2. Gastric digestion :- It occurs in
stomach.
· In stomach it wall release gastric juice
which contains Hcl(0.04), water, Mucus, Pepsin, Renin etc.
· Hydrochloric acid of gastric acid kills
the pathogens present in food and also makes food acidic for protein digestion.
· Pepsin is a protein digestive enzyme
which secreated in the form of inactive pepsinogen Renin converts milk casein
into calcium paracasein.
· In the stomach partly digested food mixed
with water of gastric juice and becomes watery called enzyme.