Life Processes

NUTRITION

  • Definition: Nutrition is the process by which a living organism obtains and utilizes food.

  • Importance: Food provides energy, growth, and development.

  • Components of Food:

    • Cereal

    • Milk

    • Cottage Cheese

    • Greek Yogurt

    • Olive Oil

  • Macronutrients:

    • Carbohydrates

    • Proteins

    • Fats

    • Vitamins & Minerals

TYPES OF NUTRITION

  1. Autotrophic:

    • Organisms prepare their own food using simple inorganic substances (e.g., carbon dioxide and water) in the presence of sunlight and chlorophyll.

    • Examples: Green plants.

    • Subtypes:

      • Photosynthesis: Using light energy to prepare food.

      • Chemosynthesis: Using chemical energy to prepare food (e.g., Purple sulfur bacteria).

  2. Heterotrophic:

    • Organisms that depend on autotrophs for their food supply directly or indirectly.

    • Types:

      • Holozoic

      • Saprophytic

      • Parasitic

RAW MATERIAL FOR PHOTOSYNTHESIS

  • Key Ingredients:

    • Sunlight: Absorbed by chlorophyll.

    • Carbon Dioxide (CO2): Enters through stomata.

    • Water: Absorbed by roots along with dissolved minerals.

  • Photosynthesis Equation:

    • 6CO2 + 6H2O -> C6H12O6 + 6O2

SITE OF PHOTOSYNTHESIS

  • Chloroplasts: Green pigmented organelles where photosynthesis occurs, containing chlorophyll.

    • Key Structures: Thylakoid, Stroma, Granum.

  • Main Events of Photosynthesis:

    • Absorption of light energy by chlorophyll.

    • Conversion of light energy into chemical energy.

    • Splitting water into hydrogen and oxygen.

    • Reduction of CO2 to carbohydrates.

CROSS SECTION OF A LEAF

  • Key Components:

    • Lamina

    • Midrib

    • Leaf Blade

    • Veins (Phloem and Xylem)

    • Vascular Bundles

    • Waxy Cuticle

    • Upper and Lower Epidermis

STOMATA AND ITS FUNCTIONS

  • Definition: Tiny pores on leaf surfaces.

  • Functions:

    • Gas exchange (O2/CO2).

    • Transpiration (water vapor loss).

  • Opening and Closing:

    • Open when guard cells swell due to water entry.

    • Close when guard cells shrink due to water loss.

HETEROTROPHIC NUTRITION

  • Definition: Type of nutrition where organisms cannot synthesize their own food and depend on others.

  • Types of Heterotrophic Nutrition:

    1. Holozoic: Solid food intake.

    • Example: Amoeba.

    1. Saprophytic: Feed on dead and decaying matter.

    • Example: Fungi like bread mold.

    1. Parasitic: Derive nutrition from living hosts without killing them.

    • Example: Tapeworm, lice.

NUTRITION IN AMOEBA

  • Process:

    1. Ingestion: Food uptake via surface.

    2. Digestion: Breakdown of food.

    3. Absorption: Nutrient uptake.

    4. Assimilation: Use of nutrients by the organism.

    5. Egestion: Removal of waste.

NUTRITION IN PARAMECIUM

  • Structure:

    • Macronucleus, Micronucleus, Cilia, Oral groove, Anal pore.

  • Food Intake: Food enters at a specific location through the oral groove.

NUTRITION IN HUMANS

  • Processes:

    • Ingestion: Intake via mouth.

    • Digestion: Breakdown in stomach/intestines.

    • Absorption: Movement of nutrients into the bloodstream.

    • Assimilation: Utilization of nutrients in cells.

    • Egestion: Waste removal via anus.

THE MOUTH (BUCCAL CAVITY)

  • Functions:

    • Intake of food with teeth involvement for chewing.

    • Tongue roles in tasting and rolling food.

    • Salivary glands produce saliva and enzymes for digestion.

STOMACH

  • Structure: J-shaped organ that mixes food with digestive juices.

  • Digestive Components:

    • Gastric juices (including Pepsin, HCL, and Mucus).

LIVER

  • Function: Secretes bile, stored in gall bladder, making food alkaline and aiding fat emulsification.

PANCREAS

  • Function: Secretes pancreatic juice with enzymes:

    • Trypsin: Protein digestion.

    • Lipase: Fat breakdown.

    • Pancreatic Amylase: Carbohydrate digestion.

ABSORPTION OF FOOD IN SMALL INTESTINE

  • Mechanism: Food absorbed via villi:

    • Increases surface area.

    • Richly supplied with blood vessels for nutrient transport.

LARGE INTESTINE

  • Functions:

    • Absorbs excess water.

    • Removal of undigested food.

  • Structure: Includes right colic, left colic, transverse colon, and others.

NUTRITION IN DESERT PLANT

  • Adaptation: Stomata open at night to reduce water loss, storing CO2 for daytime photosynthesis.

Page 24: RESPIRATION

BREATHING

  • Definition: Exchange of gases (oxygen and carbon dioxide).

    • Inhalation: Taking air inside.

    • Exhalation: Releasing air.

  • Importance: Oxygen is needed for energy production; carbon dioxide is a waste product.

PASSAGE OF AIR THROUGH RESPIRATORY SYSTEM

  • Process of Respiration: Breaking down food for energy (ATP).

    • C6H12O6 + 6O2 -> 6CO2 + 6H2O + ATP

  • Types:

    • Aerobic respiration

    • Anaerobic respiration

AEROBIC AND ANAEROBIC RESPIRATION

  • Aerobic:

    • Occurs in the presence of oxygen.

    • Takes place in mitochondria.

    • Releases more energy.

  • Anaerobic:

    • Occurs in the absence of oxygen.

    • Takes place in cytoplasm.

    • Releases less energy.

DIFFERENCE BREATHING BETWEEN RESPIRATION

  • Breathing: Intake and removal of air (physical process).

  • Respiration: Biochemical process that produces energy.

BREAKDOWN OF GLUCOSE

  • Absence of Oxygen (in yeast):

    • Ethanol + CO2 + Energy.

  • Presence of Oxygen (in mitochondria):

    • Energy + CO2 + Water.

HUMAN RESPIRATORY SYSTEM

  • Key Structures:

    • Nasal passage, mouth cavity, trachea, bronchi, lungs, diaphragm, alveoli.

PASSAGE OF AIR THROUGH RESPIRATORY SYSTEM

  • Nostril: Entrance for air.

  • Nasal Passage: Filter, warm, and moisturize air.

  • Pharynx: Air passage that doesn't collapse due to cartilage.

LARYNX & TRACHEA

  • Larynx: Contains vocal cords; involved in sound production.

  • Trachea: Connects larynx to lungs, facilitating airflow.

BRONCHI & BRONCHIOLES

  • Bronchi: Main passage into lungs for air transport.

  • Bronchioles: Smaller branches leading to alveoli.

ALVEOLI & GAS EXCHANGE

  • Alveoli: Structures for gas exchange between lungs and bloodstream.

  • Blood Capillaries: Transfer oxygen and nutrients to tissues; collect waste.

ALVEOLUS GAS EXCHANGE

  • Process: CO2 diffuses from blood to alveoli; O2 diffuses from alveoli to blood.

HEMOGLOBIN

  • Function: Iron-containing protein in RBCs for oxygen transport.

INHALATION AND EXHALATION

  • Inhalation: Diaphragm flattens, ribcage expands; air flows in.

  • Exhalation: Diaphragm arches, ribcage contracts; air flows out.

HOW DO FISHES BREATHE UNDERWATER?

  • Gills: Organs for breathing in fish; help extract dissolved oxygen.

  • Breathing Mechanism: Involves the opening and closing of gill covers.

TRANSPORTATION

  • Definition: Movement of food, water, oxygen, and waste in living organisms.

  • Circulatory System Components: Heart, arteries, veins, blood, and blood vessels.

BLOOD

  • Definition: It is a fluid connective tissue that carries oxygen and nutrients from the heart to all organs and tissues of the body.

  • Characteristics: Red fluid connective tissue, due to hemoglobin.

  • Main Components:

    • Food, hormones, CO2, metabolic wastes.

COMPONENTS OF BLOOD

  • Composition:

    • 55% Plasma (water, nutrients, waste, gases).

    • 44% RBCs.

    • 1% WBCs and platelets.

COMPONENTS OF BLOOD

  1. Red Blood Cells (RBCs): Transport oxygen using hemoglobin.

  2. White Blood Cells (WBCs): Immune system; fight infections.

  3. Platelets: Responsible for blood clotting.

FUNCTIONS OF BLOOD

  • Transportation: Carries oxygen, nutrients, hormones, and wastes.

  • Oxygenation: Delivers oxygen for energy production.

  • Immune Defense: Protects against infections.

  • Temperature Control: Regulates body temperature.

  • Clotting: Prevents blood loss at injury sites.

BLOOD VESSELS

  • Types of Vessels:

    • Arteries: Carry blood away from the heart (high pressure).

    • Veins: Carry blood towards the heart (lower pressure).

    • Capillaries: Exchange materials with tissues.

LARGE ARTERY AND VEIN

  • Aorta: Largest artery in the body.

  • Pulmonary Artery: Only artery carrying deoxygenated blood.

  • Vena Cava: Largest vein; carries deoxygenated blood back to the heart.

HUMAN HEART

  • Structure: Muscular organ with four chambers, prevents mixing of blood.

  • Chambers:

    • Atrium (Upper): Right and left atrium.

    • Ventricle (Lower): Right and left ventricle.

FLOW OF BLOOD IN HUMANS

  • Circulatory Process:

    1. Deoxygenated blood from the body enters the right atrium.

    2. Blood moves to the right ventricle and then to the lungs via pulmonary arteries for oxygenation.

    3. Oxygenated blood returns to the left atrium via pulmonary veins.

    4. Blood is pumped by the left ventricle to the body via the aorta.

CIRCULATION

  • Systemic Circulation: Blood flow from the heart to the body and back (excluding lungs).

  • Steps:

    1. Left ventricle pumps oxygenated blood to the body.

    2. Deoxygenated blood returns via the vena cava.

IMPORTANCE OF CHAMBERED HEART

  • Purpose: Prevents mixing of oxygenated and deoxygenated blood.

  • Benefit: Ensures efficient oxygen delivery and energy production.

WORKING OF HUMAN HEART

  • Cycle: Blood flow between body, lungs, and heart.

  • Key Components: Main arteries and veins related to oxygenated and deoxygenated blood.

DOUBLE CIRCULATION

  • Definition: Ensures complete separation of oxygenated and deoxygenated blood.

  • Pathway: From the heart to lungs and back, then to the rest of the body.

LYMPHATIC SYSTEM

  • Definition: Clear fluid involved in transportation within the body.

  • Formation: Formed when plasma leaks into intercellular spaces.

  • Functions: Immunity, fluid drainage, transport of fats.

DIFFERENCE BETWEEN BLOOD AND LYMPH

  • Blood: Red, contains hemoglobin, transports materials.

  • Lymph: Colorless, no hemoglobin, collects waste from tissues.

TRANSPORTATION IN PLANTS

  • Definition: Movement of water, minerals, and food throughout the plant.

  • Conducting Pathways:

    • Xylem: Water transport from roots.

    • Phloem: Food transport from leaves.

XYLEM AND PHLOEM COMPARISON

  • Xylem:

    • Conducts water and minerals from roots to leaves.

    • Composed mainly of dead elements.

    • Transport is unidirectional.

  • Phloem:

    • Conducts food from leaves.

    • Composed mainly of living elements.

    • Transport is bidirectional.

TRANSPIRATION PULL

  • Definition: Water loss as vapor from plants creates suction.

  • Importance: Aids water transport from roots to leaves, regulates temperature.

EXCRETION

  • Definition: Biological process removing harmful metabolic wastes.

  • Main Components: Left renal artery/vein, aorta, kidneys, ureters, bladder, urethra.

KIDNEY FUNCTIONS

  • Structure: Bean-shaped organs filtering blood, regulating fluids.

  • Process: Blood and waste enter through renal artery; filtered blood exits through renal vein.

NEPHRONS

  • Definition: Structural and functional unit of kidneys for waste filtration.

  • Components:

    • Bowman's Capsule: Contains glomerulus for filtration.

FORMATION OF URINE

  • Stages:

    1. Glomerular Filtration: Filtering blood components.

    2. Selective Reabsorption: Reabsorbing useful substances.

URINE FORMATION

  • Tubular Secretion: Additional waste enters urine in nephron.

  • Storage: Urine stored in the urinary bladder, regulated by nerves.

FUNCTIONING OF EXCRETION

  • Process: Glomerulus filters blood, removing harmful substances and reabsorbing useful ones.

HEMODIALYSIS

  • Definition: Medical treatment filtering blood for patients with kidney failure.

  • Components: Blood and dialysis fluid used for purification.

EXCRETION IN PLANTS

  • Methods: Diffusion of gases through stomata, transpiration of excess water, shedding old parts.