Life Process – Nutrition Notes

• Life Process:- The maintaining processes which make us alive .• 7 Life Processes :- Growth

• Movement

• Breathing

• Reproduction

• Nutrition

• Respond to stimuli

• Excretion

• Difference Between living and Non – Living Things:-

LIVING THINGS NON-LIVING THINGS

Movement- body, molecules Even though there is movement they are not alive.

Nutrition It is not taking place.

Excretion There is no excretion.

Growth Growth is not taking place.

Respiration – breathing There is no respiration.

Reproduction It is not taking place.

Sensitivity There is no sensory organs.

Metabolism:- Oxidation-reduction reactions( Metabolism) are most common inside cells to breakdown molecules of glucose ,fatty acid or amino acid .

Nutrition :- It is a process of intake of nutrients (like carbohydrates, fats, protein, minerals and water) by an organism as well as the utilization of these nutrients by the organism.

Nutrients: - These are component of food with specific function.

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Carbohydrate , Fat, Protein, Vitamin ,Minerals Fiber (Roughage), Water

Autotrophic Nutrition :- Auto = Self Trophic = to nourish

When an organisms can prepare their own food such an organism is called autotrophs and mode of nutrition is called autotrophic nutrition.

Ex. – Green Plants

Heterotrophic Nutrition: - Hetero = others ,Trophic = to nourish

When an organisms cannot prepare their own food and depends upon other organisms for food requirement is called heterotrophs and mode of nutrition is called heterotrophic nutrition.

Ex. – In animals.

Types of Heterotrophic :- 1. Chemosynthesis

2. Photosynthesis

• Chemosynthesis :- In some small organisms the production of organic compounds takes place by oxidation reaction of molecules found in surrounding.

• Ex – Sulphur bacteria, Iron bacteria

• Photosynthesis: - The process by which green plants prepare their own food ( like glucose) from carbon dioxide and water by using sunlight energy in the presence of chlorophyll, is called photosynthesis.

• 6CO2 +6H2O C6H12O6 +6O2

• Pigments of Photosynthesis:- Chlorophyll a, Chlorophyll b Carotene (Orange ),Xanthophyll(Yellow)

• Function of Chlorophyll: -

• 1 To trap solar energy

• 2 To act as catalyst

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• Cross – Section of leaf

•

• Steps of Photosynthesis: -Absorption of light energy

• Conversion of light energy to chemical energy

• Photolysis of H2O

• 2 H2O 2 H+ + O2

• Reduction of CO2 to carbohydrate

H2 + CO2 C6H12O6

Desert plant absorb CO2 at night and absorb sunlight during day.

Conditions Necessary for Photosynthesis:-

1. Sunlight

2. Chlorophyll

3. CO2

4. H2O

Experiment to Show Chlorophyll is Necessary for Photosynthesis

• Take a potted plant with variegated leaves.

• Keep the plant in the dark room for 3- 4 days to DE starch it.

• Pluck a leaf from the plant. Mark the green areas in it and trace them on a sheet of paper.

• Dip the leaf in boiling water for few minutes.

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• After this, boil the leaf in alcohol containing water bath.

• Leaf will become colorless and alcohol will become green. Remove the colorless leaf from alcohol and wash it thoroughly with water.

• Place the colorless leaf in Petri dish and drop iodine solution over it.

• Original green part of the leaf turn blue – black but not the variegated part.

• Conclusion: - Chlorophyll is necessary for photosynthesis and green part of leaf can make starch as food by photosynthesis.

• Experiment to Show Sunlight is Necessary for Photosynthesis

• Take a potted plant.

• Keep the plant in the dark room for 3- 4 days to DE starch it.

• Take a thin strip of black paper and wrap it in the center of one leaf on the both the sides.

• Keep this potted plant in sunlight for three to four days.

• Pluck the partially covered leaf from the plant and remove its black paper.

• Dip the leaf in boiling water for few minutes.

• After this, boil the leaf in alcohol containing water bath.

• Leaf will become colorless and alcohol will become green.

• Remove the colorless leaf from alcohol and wash it thoroughly with water.

• Place the colorless leaf in Petri dish and drop iodine solution over it.

• Covered portion of the leaf did not turn blue black but exposed portion of the leaf turns blue black.

• Conclusion: - Sunlight is necessary for photosynthesis and leaves makes starch as food by photosynthesis.

• Stomata: - These are tiny pores present on the surface of the leaves.

• Role of Stomata: -

• Gaseous Exchange, Transpiration

• Transpiration: - Loss of water in the form of vapour from the aerial part of the plant.

• In monocot stomata is present both the surface of leaf but in dicot stomata is present in the lower

surface. •

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CO2 is taken from atmosphere through stomata.

H2O is absorbed by root.

Types of Nutrition : - 1. Autotrophic Nutrition 2. Heterotrophic Nutrition

Types of Heterotrophic Nutrition :- 1. Saprophytic Nutrition 2. Parasitic Nutrition 3. Holozoic Nutrition

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Saprophytic nutrition: -The mode of nutrition in which organism derive its food from dead and decayed

organism. The organisms having saprophytic mode of nutrition is called saprophytes.

Ex: - Fungi, Bacteria

Parasitic Nutrition: -The mode of nutrition in which organism derive its food from other organisms by harming

it.The organisms having parasitic mode of nutrition is called parasites:- Plasmodium, Round worm, Cuscuta.

Holozoic Nutrition: -It is the kind of nutrition in which an organism intake the food materials into the body by

the process of ingestion, the ingested food is digested and absorbed into the body. Undigested and

unabsorbed food is thrown out of the body by the process of egestion.

Ex: - man, cat, dog, tiger and amoeba.

Steps of Holozoic Nutrition 1 Ingestion, 2. Digestion,3. Absorption, 4. Assimilation,5. Egestion

1. Ingestion: - The process of taking food into the body is called ingestion. Ex:- Through mouth in human

being.

2. Digestion: - The physical or chemical process in which food containing large insoluble molecules are broken

down into simple and soluble forms.

Carbohydrate Glucose, Protein Amino acid , Fat Fatty Acid +Glycerol

3.Absorption: - The process by which digested food is absorbed by the blood stream

4. Assimilation: - The process in which the absorbed food is taken in by body cells and used for energy, growth

and repair.

5. Egestion: - The process in which the undigested food is removed from the body is called egestion.

Holozoic Nutrition in Amoeba

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1. Ingestion: - Amoeba ingests food by using its pseudopodia.

2. Digestion: - Around the food a cavity called food vacuole is formed. Enzymes from cytoplasm rushes to

food vacuole and brought about digestion.

3. Absorption: - The digested food present in food vacuole is absorbed directly into the cytoplasm by

diffusion. After absorption food vacuole disappears.

4. Assimilation: - Amoeba uses absorbed food for obtaining energy and for growth.

5. Egestion: -For removal of undigested food cell membrane suddenly rupture at any place and undigested

food is thrown out of cell.

Paramaecium uses its hair like structure called cilia to sweep the food and put them into mouth.

Digestive System/ Alimentary Canal in man

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•

Alimentary Canal: -Tube like structure in human being starting from mouth and ending in anus. It is

almost 8-10 meters in adult

• Organs of Alimentary Canal: - Mouth, Buccal cavity, Esophagus, Stomach, Small intestine, Large

Intestine, Rectum and Anus.

• Glands of Alimentary Canal: - Salivary Glands, Liver, Pancreas, Gastric Glands

1. Digestion in Human Being: -

Mouth: - Ingest food

Buccal Cavity :-Contains three pairs of salivary glands which produces saliva ; saliva makes the food wet so

that it can be swallowed easily. Saliva contain an enzyme called Salivary amylase which breaks down starch to

give maltose and isomaltose.

Starch (Salivary Amylase) Maltose + Isomaltose

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Teeth :-It crushes the food into smaller particles and does physical digestion.

Tongue : - It tastes food and mixes food with saliva.

Esophagus :- It performs peristaltic movement.

Peristaltic Movement: -The rhythmic contraction and relaxation of alimentary canal.

Stomach: - The wall of stomach has gastric glands which secrete gastric juices which digest protein.

Composition of Gastric Juice : - HCl, pepsin and Mucus

- HCl acid provides acidic medium for the action of pepsin. It kills germs.

- Protein (Pepsin) Amino Acid

- Mucus protects the inner lining of stomach from acid.

- Between stomach and small intestine, a sphincter muscle is present which regulate the release of food

from stomach to small intestine.

• Small Intestine :- It is the site of complete digestion of food. It receives secretion of bile and pancreas

for this purpose.

Bile Juice: - It is the secretion of liver which is stored in gall bladder.

Function of Bile Juice: -1. It provides alkaline medium for the activation of pancreatic juice.

2. Emulsification of Fat: - Breaking down of bigger fat molecules into small globules by bile juice

Function of Pancreatic Juice : - Pancreatic juice contain trypsin, amylase and lipase.

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Trypsin acts on protein, amylase works on starch and lipase on fat.

- Starch(Amylase) Maltose + Isomaltose

- Protein (Trypsin) Amino Acid

- Fat (Lipase) Fatty Acid + Glycerol

Function of Intestinal Juice: - The wall of intestine secrete intestinal juice which brought about complete

digestion of food. Starch Glucose

FatFatty Acid +Glycerol

Protein Amino Acid

Absorption of food by Small Intestine: - The inner lining of small intestine contains numerous finger like

projections called villi and microvilli which increases the surface area for absorption. Villi are provided by

numerous blood capillaries.

Egestion: - Villi of large intestine absorbs water from unabsorbed food and then egested out of the body

through anus.

The exit of the anus is regulated by anal sphincter.

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Dental Caries: -The formation of small cavities in the teeth due to the action of acid forming bacteria and

improper dental care are called dental caries.

Dental plaque: - If the teeth are not cleaned properly, then they become covered with a sticky yellowish

layer of food particles and bacterial cell called dental plaque.

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