Life Processes class 10 Science Biology | CBSE NCERT | Oneshot

Key Concepts:

• Life Processes: Processes essential for survival and maintenance of body functions.
• Nutrition: The process of obtaining nutrients from food.
• Autotrophic Nutrition: Organisms producing their own food from inorganic materials (e.g., plants).
• Heterotrophic Nutrition: Organisms depending on other organisms for food (e.g., humans, animals).
• Respiration: The process of obtaining energy by combining oxygen and glucose.
• Aerobic Respiration: Energy production in the presence of oxygen.
• Anaerobic Respiration: Energy production in the absence or lack of oxygen.
• ATP (Adenosine Triphosphate): Energy currency of the cell.
• Transport: Movement of substances within the body.
• Blood: Connective tissue for transporting substances in humans.
• Xylem: Plant tissue for transporting water and minerals.
• Phloem: Plant tissue for transporting food.
• Transpiration: Loss of water vapor from plant parts.
• Translocation: Transport of food from leaves to other plant parts.
• Excretion: Removal of waste products from the body.
• Nephron: Functional unit of the kidney for filtering blood.

Nutrition

Definition and Importance

Life processes are essential for maintaining body functions and survival. Nutrition is the process of taking nutrients from food. Key nutrients include carbohydrates, fats, proteins, water, vitamins, minerals, and iodine.

Modes of Nutrition

• Autotrophic Nutrition: Organisms like green plants produce their own food using inorganic materials (water and CO2) in the presence of sunlight. This process is called photosynthesis.
  • Chemical Reaction: 6CO2 + 6H2O → C6H12O6 + 6O2 (Carbon dioxide + Water → Glucose + Oxygen) in the presence of sunlight and chlorophyll.
  • Events during Photosynthesis:
    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 carbon dioxide to carbohydrates.
• Heterotrophic Nutrition: Organisms depend on other organisms for food. Examples include humans and amoeba.
  • Types of Heterotrophic Nutrition:
    • Saprophytic: Obtaining food from dead and decaying organic matter (e.g., bacteria, fungi).
    • Parasitic: Obtaining food from another organism without killing it (e.g., mosquitoes, tapeworms).
    • Holozoic: Ingestion, digestion, absorption, and assimilation of liquid or solid organic materials (e.g., humans, animals).

Nutrition in Humans

• Mouth: Intake of food. Teeth break food into smaller pieces, and the tongue tastes and rolls the food.
• Salivary Glands: Produce saliva containing salivary amylase, which breaks down starch into simple sugars.
• Esophagus: Transports food from the mouth to the stomach through peristaltic movements.
• Stomach:
  • Gastric glands release gastric juice containing:
    • HCl: Makes the medium acidic to kill bacteria.
    • Pepsin: Breaks down proteins into amino acids.
    • Mucus: Protects the inner lining of the stomach from HCl.
• Small Intestine: Site of complete digestion.
  • Liver: Produces bile juice (makes food alkaline) and bile salts (emulsification of fats).
  • Gallbladder: Stores bile juice and bile salts.
  • Pancreas: Releases trypsin (breaks down proteins into amino acids) and lipase (breaks down emulsified fats into fatty acids and glycerol).
• Villi: Finger-like projections in the small intestine that increase the surface area for absorption. They supply the absorbed food to blood vessels, which transport it to every cell.
• Large Intestine: Absorbs water from undigested food. The remaining material is removed from the body via the anus.

Nutrition in Plants

• Plants convert inorganic food material into complex organic food material in the presence of chlorophyll and sunlight.
• Chemical Reaction: 6CO2 + 6H2O → C6H12O6 + 6O2 (Carbon dioxide + Water → Glucose + Oxygen) in the presence of sunlight and chlorophyll.
• Chloroplasts: Small organelles in plant cells containing chlorophyll, which absorbs sunlight for photosynthesis.

Respiration

Definition and Types

Respiration is the process in which cells obtain energy by combining oxygen and glucose. It involves breathing.

• Aerobic Respiration: Energy production in the presence of oxygen.
• Anaerobic Respiration: Energy production in the absence or lack of oxygen.

Respiration Process

• Glucose Breakdown: Glucose (C6H12O6) is broken down in the cytoplasm into pyruvate and energy.
  • Absence of Oxygen (Yeast): Pyruvate → Ethanol + Carbon Dioxide + Energy
  • Lack of Oxygen (Muscles): Pyruvate → Lactic Acid + Energy
  • Presence of Oxygen (Cells): Pyruvate → Carbon Dioxide + Water + Energy
• ATP: The energy released during respiration is used to synthesize ATP (Adenosine Triphosphate), the energy currency of the cell.

Human Respiratory System

• Components: Nose, nasal cavity, pharynx, larynx, trachea, bronchi, lungs, alveoli, diaphragm.
• Process:
  1. Oxygen-rich air is inhaled through the nose and filtered by hairs.
  2. Air passes through the throat to the lungs.
  3. Air passages divide into smaller tubes and reach the alveoli.
  4. Alveoli (balloon-like structures) provide a surface for gas exchange.
  5. Oxygen dissolves in hemoglobin and is carried to cells.
  6. Carbon dioxide from cells is released into the alveoli and exhaled.

Respiration in Plants

• Gas Exchange: Occurs through stomata (leaves), lenticels (stems), and root surfaces.
• Process: Plants absorb oxygen and use it with glucose to create carbon dioxide, water, and energy.
• Chemical Reaction: C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (Glucose + Oxygen → Carbon Dioxide + Water + Energy)

Transport

Transport in Humans

• Blood: Connective tissue that transports necessary substances to cells and metabolic waste away from cells.
  • Components:
    • Plasma: Transports food, CO2, and waste products.
    • Red Blood Cells (RBCs): Contain hemoglobin, which transports oxygen.
    • Platelets: Help in blood clotting.
    • White Blood Cells (WBCs): Fight against harmful bacteria, viruses, and germs.
• Heart: Pumps blood through blood vessels.
  • Chambers: Right atrium, right ventricle, left atrium, left ventricle.
  • Process:
    1. Deoxygenated blood enters the right atrium from the body.
    2. Blood flows to the right ventricle, which pumps it to the lungs.
    3. In the lungs, carbon dioxide is released, and oxygen is absorbed.
    4. Oxygenated blood enters the left atrium from the lungs.
    5. Blood flows to the left ventricle, which pumps it to the body.
• Blood Vessels:
  • Arteries: Carry oxygenated blood from the heart to body parts (except pulmonary artery). They are thick and elastic.
  • Veins: Carry deoxygenated blood from body parts to the heart (except pulmonary vein). They are thin and less elastic.
  • Capillaries: Smallest vessels (one cell thick) that connect arteries and veins.
• Lymph: A transporter fluid formed from plasma, proteins, and blood cells that escape into intercellular spaces.

Transport in Plants

• Xylem: Transports water and minerals from roots to the highest point of the plant (upward direction only). Works on the principle of transpiration.
• Phloem: Transports food from leaves to other parts of the plant (upward and downward directions). The transport of food is called translocation.
• Transpiration: The process of water loss as vapor from aerial parts of the plant.

Excretion

Definition and Process

Excretion is the process of removing waste products from the body.

Human Excretory System

• Components: Two kidneys, ureters, urinary bladder, and urethra.
• Kidneys: Filter blood and remove waste.
  • Nephrons: Filtration units of the kidneys.
    • Bowman's Capsule: Filters blood and collects urine.
    • Loop of Henle: Reabsorbs glucose, amino acids, and water.
• Ureters: Drain urine from the kidneys to the urinary bladder.
• Urinary Bladder: Stores urine.
• Urethra: Transmits urine outside the body.

Excretion in Plants

• Oxygen Removal: Through stomata.
• Excess Water Removal: Through stomata by transpiration.
• Other Waste Removal: Through loss of old leaves and bark.

Synthesis/Conclusion

The video provides a detailed explanation of the four essential life processes: nutrition, respiration, transport, and excretion. It covers the mechanisms in both plants and humans, including the specific organs, tissues, and chemical reactions involved. Key concepts such as autotrophic and heterotrophic nutrition, aerobic and anaerobic respiration, the roles of xylem and phloem, and the function of the nephron are thoroughly explained. The video emphasizes the importance of these processes for survival and maintenance of life.