NUTRITION AND RESPIRATION CLASS - X

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NUTRITION AND RESPIRATIONCLASS - X
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LIFE PROCESS

• The basic functions performed by living organisms
  to maintain their life on this earth are called
  life processes.
• The basic life processes common to all the living
  organisms are
• Nutrition and Respiration
• Transport and Excretion
• Control and Coordination
• Growth
• Movement and Reproduction

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NUTRITION

• Nutrient It is a substance which an organism
  obtains from its surroundings and uses it either
  as an energy source or for biosynthesis of body
  constituents.
• Example- Proteins, Carbohydrate,Fats etc.
• Nutrition It is a process of intake of
  nutrients as well as utilisation of nutrients by
  an organism.

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MODE OF NUTRITION

• Mode of nutrition means method of procuring food
  or obtaining food by an organism. Depending on
  the mode of obtaining food, all organisms can be
  classified into two groups,
• Autotrophic
• Heterotrophic

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AUTOTROPHIC MODE OF NUTRITION

• Auto means self and troph means to nutrition,
  thus autrotrophic means self nutrition.
• It can be defined as a type of nutrition in which
  organisms synthesise its own food
• ( Organic material) from the simple inorganic
  materials like carbon dioxide and water.
• Exa Green plants, autotrophic bacteria

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HETEROTROPHIC MODE OF NUTRITION

• The word hetero means other and troph means
  nutrition, which means nutrition obtained from
  others.
• Heterotrophic nutrition can be defined as a mode
  of nutrition in which an organism cannot make its
  own food from simple inorganic materials like
  carbon dioxide and water, and depends on other
  organisms for its food.
• Example- All animals, bacteria and fungi.

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• Heterotrophic nutrition is of three types which
  are as follows --
• Saprophytic Nutrition
• Parasitic Nutrition
• Holozoic Nutrition

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SAPROPHYTIC NUTRITION

• The word sapro means rotten.
• Saprophytic mode of nutrition is a nutrition in
  which an organism obtains its food from dead and
  decaying organic matter.
• Example- Fungi and bacteria
• Such organisms are called saprophytes.

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PARASITIC NUTRITION

• The word para means others.
• The parasitic nutrition is a nutrition in which
  an organism derives its food from the body of
  another living organism(called its host).
• The organism which obtains food is called
  parasite and the organism from whose body food is
  obtained is called host.
• Example of parasite Plasmodium, Cuscuta,
  roundworm

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HOLOZOIC NUTRITION

• Holozoic nutrition means feeding on solid food.
• The holozoic nutrition is a nutrition in which an
  organism takes the complex organic food materials
  into its body by the process of ingestion, which
  is subsequently digested and obsorbed.
• Example Amoeba, frog, human beings.

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NUTRITION IN PLANTS

• PHOTOSYNTHESIS The process by which green
  plants make their own food ( like glucose) from
  carbon dioxide and water by using sunlight energy
  in the presence of chlorophyll, is called
  photosynthesis.
• Oxygen gas is released during this process.
• The overall equation of photosynthesis is
  represented as follows
• Sunlight
• 6CO2 12 H2O ?C6H12O6 6H2O 6O2
• chlorophyll

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CLOROPLAST
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STRUCUTE OF CHLOROPLAST

• STRUCTURE - In the chloroplast of higher plants,
  
• Stacks of thylakoids(lamellar structures) are
  present which are called grana (sing.-granum).
• Thylakoid is a flattened sac of membrane which
  contains chlorophyll molecules responsible for
  Photosynthesis. The Light dependent reaction (or
  light reaction) of photosynthesis occurs in the
  thylakoids.

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• A thylakoid of one granum is connected to other
  granum with the help of stroma lamellae (single
  thylakoid).
• The chloroplast is filled with a liquid called
  stroma or matrix. The light independent reaction
  (or dark reaction) occurs in the stroma of the
  chloroplast.
• A double membrane surrounds the entire
  chloroplast.

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CHLOROPLAST

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PORTION OF THE LEAF

• LEAF SECTION

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A PLANT CELL
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CHLOROPHYLL

• Chlorophyll and carotenoid pigments are
  photoreceptor molecules which play a key role in
  photosynthesis.
• The green colour of plant is due to the presence
  of chlorophyll.
• Different types of chlorophyll are
• Chlorophyll a, b, c, d, e and bacteriochlorophyll
• Chlorophyll a and b are most common and are found
  in all plants.
• Chlorophyll pigments are found inside
  chloroplasts.

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CHLOROPHYLL MOLECULE
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CHLOROPHYLL
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CAROTENE
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PHOTOSYNTHESIS

• PHOTOSYNTHESIS The process by which green
  plants make their own food ( like glucose) from
  carbon dioxide and water by using sunlight energy
  in the presence of chlorophyll, is called
  photosynthesis.
• Oxygen gas is released during this process.
• The overall equation of photosynthesis is
  represented as follows
• Sunlight
• 6CO2 12 H2O ?C6H12O6 6H2O 6O2
• chlorophyll

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SOLAR RADIATION
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RAW MATERIALS FOR PHOTOSYNTHESIS

• The raw materials for photosynthesis are
• 1) Chlorophyll
• 2) Sunlight
• 3) Carbon dioxide
• 4) Water

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STOMATA
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MECHANISM FOR PHOTOSYNTHESIS

• The entire process of photosynthesis can be
  divided into two main stages.
• 1) Light reaction Light dependant
• 2) Dark reaction Light independent

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LIGHT REACTION

1. When light strikes chlorophylls, photons are
   absorbed which excite electrons of chlorophylls
   to a higher energy level. The emitted electrons
   travel through the electron transport chain
   present in the chloroplast. The process requires
   a number of electron acceptors
2. In this process ATP is synthesized from ADP and
   inorganic phosphate. This ATP is used as a source
   of energy during dark reaction.

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1. In light reaction photolysis of water takes
   place.
2. 2H2O ? 4H O2 4e-
3. The hydrogen ions which is released during
   photolysis reduce the NADP molecule
   (Nicotianamide adenine diphosphate) into NADPH2
   which is also used during the dark reaction. It
   is important to note that oxygen released during
   photosynthesis comes from water.

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PHOTOPHOSPHORYLATION
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ATP MOLECULE
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DARK REACTION

1. The NADPH2 molecule as well as ATP(assimilatory
   power) produced during the light reaction are
   utilized in the stroma of chloroplast for
   synthesis of carbohydrate from CO2. This is
   called carbon fixation
2. In this process CO2 enters into a series of
   reactions with Ribulose biphosphate ( five
   carbon sugar). At the end carbohydrate is
   synthesized and Ribulose biphosphate is
   regenerated. This is called Calvin-Benson cycle.
   After its discoverer Melvin Calvin Ande Benson.

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FACTORS NECESSARY FOR PHOTOSYNTHESIS

• A number of factors affect the process of
  photosynthesis, as a result of which productivity
  is affected. These are
• Carbon dioxide
• Water
• Chlorophyll
• Light
• Temperature

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CARBON DIOXIDE (CO2)

• Air contains 0.03 of CO2. It is released by
  respiration, combustion of fossil fuels and
  microbial decomposition.
• During early morning hours and evening hours, CO2
  released in respiration is sufficient for
  photosynthesis. At this stage, there is no
  exchange of gases between the plant and the
  environment. This is called compensation point.

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• An increase in the concentration of CO2 upto 0.1
  increases the rate of photosynthesis.
• Higher concentration of CO2 decreases the rate of
  photosynthesis.

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WATER

• Plants absorb water and mineral salts through
  root hair and pass it to the leaves through
  xylem.
• If there is less availability of H2O, then
  stomata closes ( to reduce the water loss by
  transpiration) and there is decreased CO2
  absorption and sunlight absorption.
• Therefore the rate of photosynthesis decreases.

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CHLOROPHYLL

• Only cells having chlorophyll are photosynthetic.
  There is no proportionality between the rate of
  photosynthesis and amount of chlorophyll.

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LIGHT

• White light consists of all the seven colours.
  Highest rate of photosynthesis is seen in red
  light and minimum in green light. Chlorophyll can
  absorb violet, blue and red light rays.
• The rate of photosynthesis increases at the lower
  intensity of light and decreases in the stronger
  intensity of light.

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TEMPERATURE

• Photosynthesis is an enzymatic process. The
  enzymes function within an optimum range of
  temperature.
• Lower temperature has an inhibitory effect on the
  rate of photosynthesis because the enzymes are
  inactivated.
• Increase in temperature increases the rate of
  photosynthesis but it ultimately inhibits
  photosynthesis.

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CARBON DIOXIDE

• The rate of photosynthesis increases with an
  increase in carbon dioxide concentration upto a
  certain level.
• Beyond that, CO2 concentration has no effect on
  the rate of photosynthesis. On the contrary it
  decreases the rate.

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NUTRITION IN AMOEBA

• Amoeba is a unicellular animal which feeds on
  microscopic animals and plants that float in a
  water body.
• The mode of nutrition in amoeba is holozoic.
• The process of obtaining food in amoeba is termed
  as phagocytosis.
• The various steps of nutrition are ingestion,
  digestion, assimilation and egestion.

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AMOEBA
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• Amoeba engulfs the food by forming pseudopodia.
• When the food is completely encircled and the
  tips of encircling pseudopodia touch each other,
  the membrane at that point dissolves.
• The food is encaptured into the cell like a bag
  called food vacuole.
• Inside the food vacuole, the food gets digested
  by digestive enzymes.

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• The digested food diffuses into the cytoplasm and
  is utilised by the cell. This is termed as
  assimilation.
• The undigested food remains in the food vacuole,
  and is thrown out of the body.
• This process is called egestion.

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NUTRITION IN GRASSHOPPER

• Grasshopper is herbivorous which feeds mainly on
  leaves of plants.
• The mouth parts in grasshoppers are adapted for
  biting and chewing.

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DIGESTIVE SYSTEM OF GRASSHOPPER

• The digestive system of grasshopper can be
  divided into
• Foregut mouth, pharynx, oesophagus,
  crop, salivary glands, gizzard
• Midgut stomach, hepatic caeca
• Hindgut ileum, colon, rectum and anus
• ?Malphigian tubules are present in between midgut
  and hindgut.