CBSE Class 10 Science Life Processes Notes Set 07

LIFE PROCESSES

All the vital processes which are required by an organism to survive are called life processes.

Nutrition, photosynthesis, transportation, metabolism, respiration, reproduction, and excretion are important life processes.

IMPORTANT LIFE PROCESSES

• NUTRITION
• TRANSPORTATION
• EXCRETION

NUTRITION

The process, by which an organism takes food and utilizes it, is called nutrition.

Nutrition is essential for the growth and development of organisms. It also provides energy to do different work.

NUTRIENTS

• Macronutrients(Carbohydrates, proteins and fats)
• micronutrients (Minerals and vitamins)

HOW DO LIVING THINGS GET THEIR FOOD?

Autotrophic Nutrition: Perform photosynthesis.

Heterotrophic Nutrition: Can not perform photosynthesis.

AUTOTROPHIC NUTRITION

The mode of nutrition in which an organism prepares its own food is called autotrophic nutrition. Green plants and blue-green algae make their food by a process called photosynthesis.

PHOTOSYNTHESIS

• The process by which plants in the presence of pigment, sunlight, water, and carbon diox to form food and release oxygen is known as photosynthesis.
• The overall reaction occurring in photosynthesis is as follows:

\[ 6\text{CO}_2 + 12\text{H}_2\text{O} \xrightarrow{\text{Sunlight and chloroplast}} \text{C}_6\text{H}_{12}\text{O}_6 \text{ (Glucose)} + 6\text{O}_2 + 6\text{H}_2\text{O} \]

PHOTOSYNTHESIS – Raw Material and Events

Oxidation- Reduction Process of Photosynthesis:

• Absorption of light energy by chlorophyll.
• Conversion of light energy to chemical energy.
• Splitting of \( \text{H}_2\text{O} \) in \( \text{H}^+ \) and \( \text{O}_2 \).
• Reduction of \( \text{CO}_2 \) into carbohydrates.

Chloroplast

It contains the main photosynthetic pigment chlorophyll and accessory pigments xanthophyll and carotenoids.

Stomata

Gaseous exchange and transpiration (loss of water as water vapors) take place through ma inute aperture on the surface of leaves called stomata. Stomata has a pore (stomata pore) guarded bybean shape guard cells (regulate the opening and closing of stomata.

HETEROTROPHIC NUTRITION

In this type of nutrition, organisms obtain their nutrient from other living organisms (parasites) e.g.Animals or dead and decaying objects (saprophytes e.g. Fungi like bread molds, yeast and mushrooms.

TYPES OF HETEROTROPHIC NUTRITION

• Saprotrophic Nutrition: Feed on dead & decaying matter. Include bacteria & fungi which digest the food externally before the nutrients are absorbed.
  Example: Fungi, Bread moulds
• Parasitic Nutrition: Obtains nutrients from living organisms. The parasite obtains nutrients by living on or in the body of the host.
  Example: Cuscuta, Tapeworm
• Holozoic Nutrition: The organism feed by ingesting solid organic matter which is then digested and absorbed into their bodies.
  Example: Human Beings, Animals

HUMAN DIGESTIVE SYSTEM

• Food is crushed and mixed with saliva with the help of teeth and tongue.
• Saliva contains salivary amylase that breaks down starch.
• By peristaltic movement in the oesophagus the food enters the stomach.
• In the stomach food is mixed with HCl, Protein digesting enzyme pepsin, and Mucus.
• HCl kills the germs in food as well as provides an acidic medium essential for pepsin.
• Mucus protects the inner lining of the alimentary canal by HCl.
• Small intestine receives secretions from the liver and pancreas through a common duct.
• Unabsorbed food enters the large intestine for further absorption of water.
• Undigested food is removed from the body via anus.

DIGESTIVE SYSTEM ORGANS AND THEIR ROLES

• LIVER: Secretes BILE JUICE.
  Role: Make medium alkaline for pancreatic juice. Break the fat molecules into smaller parts (emulsification).
• PANCREAS: Secretes PANCREATIC JUICE.
  Role: Trypsin digest protein and Lipase digest lipid
• SMALL INTESTINE: Secretes INTESTINAL JUICE.
  Role: Convert Proteins to amino acids, Carbohydrates to glucose, Fat to fatty acid and glycerol

DENTAL CARIES (TOOTH DECAY)

It is caused due to acid produced by bacteria. In this enamel softens and may cause dental plaque and cavities.

RESPIRATION

The process of Breaking complex organic material into a simpler form with the help ofenzymes is called reparation.

Keywords

• Cytoplasm: Fluid part within the cell
• Mitochondria: Site of energy production (the powerhouse of the cell)
• Pyruvate: The intermediate product of respiration
• Ethanol: A type of alcohol (\( \text{C}_2\text{H}_5\text{OH} \))
• ATP: Adenosine triphosphate, an energy-rich compound

Types of respiration and site

PROCESS OF RESPIRATION

• Glucose is broken down into pyruvate in the cytoplasm of a the cell.
• In the presence of oxygen, pyruvate enters into mitochondria and completely oxidized there to produce \( \text{CO}_2 \) and energy (ATP).
• In the absence of oxygen pyruvate partially decompose and form. Eg- Ethanol in yeast (fermentation), b- Lactic acid in muscle cells

HUMAN RESPIRATORY SYSTEM

(consists of the nostril, nasal passage, pharynx, larynx, trachea, bronchi, bronchioles, alveoli,diaphragm, and ribcage.)

• The inhale of oxygen and exhale of \( \text{CO}_2 \) is known as breathing. Air is taken into body through nostrils.
• From nostril air passes through the pharynx, larynx, trachea, bronchi, bronchioles and finally alveoli.
• At alveoli exchange of oxygen and \( \text{CO}_2 \) takes place with blood vessels by process of diffusion.
• Oxygen enters into blood vessels while \( \text{CO}_2 \) enters into the alveolar sac. Both oxygen and \( \text{CO}_2 \) is carried by iron-containing hemoglobin.

TRANSPORTATION IN HUMAN BEINGS

• Blood: Connective tissue consists of RBC, WBC, Platelets and plasma.
• Plasma: The fluid portion of the blood
• Systole: Contraction of heart chambers
• Diastole: Relaxation of heart chambers
• Double circulation: Blood goes through the heart twice
• Arteries: Thick-walled. elastic, Carry blood away from heart to various organs
• Veins: Thin-walled, carry blood from different organs to the heart
• Platelets: Helps in blood clotting during an injury
• Lymph / Tissue fluid: Fluid in intercellular space in the tissues. They carry digested and
• Sphygmomanometer: Measure blood pressure

HEART

• 2 chamber (Fish): 1 atrium, 1 ventricle
• 3 chamber (Amphibian): 2 atrium, 1 ventricle
• 4 chamber (Human): 2 atrium, 2 ventricle

Human Heart

• 2 atrium and 2 ventricle
• The atrium and ventricles are separated to avoid mixing of oxygenated and deoxygenated blood
• The right atrium and right ventricle contain deoxygenated blood while the left atrium and left ventricle contain oxygenated blood.
• Oxygenated blood from the lungs enters in left atrium via pulmonary veins. When the left atrium contracts (systole) blood enters to left ventricle. The blood goes outside to different parts of body via the aorta when the left ventricle contracts.
• From different parts of the body deoxygenated blood is carried out by the superior and inferior vena cava to the right atrium.
• When right atrium contracts the blood enters into right ventricle. The deoxygenated blood goes to the lungs through pulmonary arteries when right ventricle contracts.

TRANSPORTATION IN PLANTS

• Stomata: Gaseous exchange, Transportation (loss of water in form of vapor)
• Xylem: Water conduction channels composed of xylem tissue, vessels and tracheid. Transport water and mineral from root to aerial part (unidirectional)
• Phloem: Transport food from the leaves to other part (multidirectional).

EXCRETION

• Excretion: Removal of harmful metabolic wastes from the body
• Kidney: Excretory organ of human
• Nephron: Structural and functional unit of kidney
• Urinary bladder: Store urine
• Ureter: Connect urinary bladder with kidney
• Hemodialysis: Artificial kidney, a device to remove nitrogenous waste products (urea, uric acid) from the blood.

EXCRETION IN HUMAN BEINGS

• Basic filtration units in kidneys are clusters of thin-walled capillaries. These are associated with cup-like structure which collects the filtered urine.
• There is reabsorption of glucose, amino acids, salts, and water in tubules of nephrons.
• The concentrated urine enters into urinary bladder via the ureter and finally passes outsidethe body through the urethra.

EXCRETION IN PLANTS

• Stomata play an important role as is the site for gaseous exchange and transpiration.
• Some waste products are released in form of resin, gums.
• Falling of leaves also helps in the removal of waste products.