Ch 06: Biological Process | Exam Fusion Prep

⚗️ Metabolic / Life Processes

Nutrition

Getting nutrients from food

Respiration

Energy release from food

Excretion

Removal of metabolic wastes

Transportation

Moving substances in body

🌿 1. Autotrophic Nutrition (Plants)

Formation of food (organic matter) from simple inorganic elements
Food prepared by Photosynthesis (in presence of Chlorophyll)

6CO₂ + 12H₂O + Sunlight → (Chlorophyll) → C₆H₁₂O₆ + 6O₂ + 6H₂O

Nutrient Sources

H, O → Water (H₂O)
C, O → Air (CO₂)
Others → Soil mineral elements
Macronutrients: C, H, O, N, P, K, Ca, Mg, S
Micronutrients: Fe, B, Zn, Mn, Cu, Mo, Cl

Special Plants

Insectivorous: Eat insects (lack of N in soil)
e.g. Nepenthes, Drosera, Venus flytrap
Parasites: Depend on other plants (sucker roots)
e.g. Cuscuta (complete stem parasite)
Symbiotic: Both organisms benefit
e.g. Legume root nodules + Rhizobium (N-fixing)

🐾 2. Heterotrophic Nutrition

Unable to make own food — gets nutrition from living organisms

Holozoic

Ingest → Digest → Absorb nutrients
e.g. Human, Amoeba, Goat, Lion

Saprophytes

Extracellular digestion of dead/decayed matter
e.g. Rhizopus, Yeast, Penicillium

Parasites

Live inside/outside host body
e.g. Ticks, Lice, Leech, Tapeworm, Pathogenic bacteria

⚠ Exam Trap

Cuscuta = Complete stem parasite with sucker roots. Rhizobium = Symbiotic N-fixing bacteria in legume root nodules, not a parasite.

📊 Macronutrients — Energy Values

Nutrient	Energy / gram	Composition	Examples / Sources	Deficiency
Carbohydrate	≈4 kcal	C : H : O = 1:2:1	Glucose, Starch, Lactose, Fructose — Honey, Potatoes, Wheat, Fruits	Low energy
Protein	≈4 kcal	C + H + O + N + S/P	Keratin, Collagen, Haemoglobin, Casein (milk), Insulin, Gluten (wheat) — Pulses, Meat, Eggs	Kwashiorkor (protein deficiency); marasmus (protein–energy malnutrition)
Fat	≈9 kcal	Fatty acid + Ester of Glycerol (C, H, O)	Phospholipids, Cholesterol — Coconut, Mustard oil, Ghee, Butter, Meat	—

⚠ Exam Trap

Fat = ≈9 kcal/gm (highest energy!). Protein = ≈4 kcal/gm. Carb = ≈4 kcal/gm (same energy as protein). Nutritional deficiency = Kwashiorkor (protein deficiency); marasmus (protein–energy malnutrition). Term 'Vitamin' coined by Casimir Funk.

💧 Water & Minerals

Water = 65–70% of body; inorganic solvent
Minerals: Simple inorganic nutrients

Examples:Fe, Zn, Mg, Cl, Ca, P, S, K, F, Na, Cu, I, Mo, Cr, Mn, Co, Se

⚡ Quick Recall

Essential amino acids (9): His, Ile, Leu, Lys, Met, Phe, Thr, Trp, Val — body cannot synthesize them. Phenylalanine → tyrosine → catecholamines, thyroxine and melanin. Melatonin is derived mainly from tryptophan.

🧡 Fat-Soluble Vitamins (A, D, E, K)

Vitamin	Chemical Name	Deficiency Disease / Effect
Vitamin A	Retinol; β-carotene is a provitamin A precursor	Night blindness, Xerophthalmia, corneal damage such as keratomalacia
Vitamin D	Calciferol	Rickets (children), Osteomalacia (adults), weakening of teeth, bones, muscles
Vitamin E	Tocopherol	Neuromuscular problems and haemolytic anaemia; historically called the anti-sterility vitamin
Vitamin K	Phylloquinone (Vitamin K₁)	Excess bleeding (failure of blood clot formation)

⚠ Exam Trap

Fat soluble = A, D, E, K. Water soluble = B complex + C. Vitamin K = blood clotting — deficiency causes bleeding. Vitamin D = Rickets (children) / Osteomalacia (adults).

💧 Water-Soluble Vitamins (B complex, C)

Vitamin	Chemical Name	Deficiency Disease / Effect
B₁	Thiamine	Beri-Beri (polished rice), carbohydrate metabolism affected
B₂	Riboflavin	Cheilosis
B₃	Nicotinic Acid / Niacin	Pellagra (3D)
B₅	Pantothenic Acid	Deficiency is rare; fatigue, irritability and neurological symptoms may occur
B₆	Pyridoxine	Dermatitis, anaemia, neurological symptoms and convulsions may occur
B₇	Biotin	Skin diseases, hair loss
B₉	Folic Acid	Megaloblastic anaemia; increased risk of fetal neural-tube defects
B₁₂	Cobalamin	Megaloblastic anaemia with possible neurological dysfunction
C	Ascorbic Acid	Scurvy; impaired collagen formation and reduced iron absorption

⚡ Quick Recall — Vitamin Mnemonics

B₁ = Beri-Beri | B₃ = Pellagra (3D: Dermatitis, Diarrhoea, Dementia) | C = Scurvy | D = Rickets | K = Klotting (clotting)

🍽️ Digestive System — Overview

Process:Ingestion → Digestion → Absorption → Assimilation → Defecation Alimentary canal length:8–10 m (Mouth to Anus)

Part	Length / Shape	Key Function
Pharynx	12 cm	Common passage for food and air; epiglottis prevents food entering trachea
Oesophagus	22–24 cm	Peristaltic movement (pushes food down)
Stomach	25 cm, J-shaped	Protein digestion, Chyme formation (pH 2.0)
Small intestine	Duodenum (25cm) + Jejunum (2.4m) + Ileum (3.5m)	Complete digestion + absorption by microvilli
Large intestine	Caecum (6cm) + Colon (1.3m) + Rectum (12–15cm)	Water absorption, faeces formation & disposal

🦷 Teeth & Tongue

Adult Teeth (32 total)

4 Incisors — cutting
2 Canine — tearing and ripping
4 Premolars — chewing/grinding
6 Molars — chewing/grinding
× 2 jaws = 32 teeth
Formula: 2,1,2,3 / 2,1,2,3 × 2 = 32
Children's formula: 2,1,0,2 / 2,1,0,2
Wisdom tooth = Third molar
Outer: Enamel (hardest) | Inner: Dentine

Taste Buds — No Exclusive Taste Zones

Basic tastes → sweet, salty, sour, bitter and umami
Taste buds contain sensory receptor cells
Most taste-bud-bearing regions detect multiple basic tastes
Regional sensitivity may vary; tastes are not confined to exclusive zones

Elephant ivory → enlarged upper incisors (tusks), mainly dentine

🧪 Digestive Glands & Enzymes

Location	Gland	Key Enzymes	Acts on
Buccal cavity	Salivary gland	Ptyalin / Amylase	Starch
Stomach (pH 2.0)	Gastric gland (HCl + mucus)	Pepsin, Rennin, Gastric lipase	Protein, Milk protein, Fat
Duodenum (pH 7.5–8.2)	Pancreas	Trypsin, Chymotrypsin, Amylopsin, Carboxypeptidase, Lipase	Protein, Starch, Complex sugar, Polypeptide, Fat
Small intestine	Intestinal glands	Enterokinase, Erepsine, Maltase, Sucrase, Lactase, Lipase, Nuclease	Trypsinogen, Maltose, Sucrose, Lactose, Fat, Nucleotides

🏭 Digestive Glands — Key Facts

Liver: Largest gland | Kupffer cells (macrophages) | Emulsification of fat | Bile juice (pH 7.4–8.5, stored in gall bladder) | Glycogenesis | Detoxification | Urea formation | Stores Vitamins A, D, E, K
Pancreas: Second largest gland | Mixed gland | Pancreatic juice
Salivary glands: 3 pairs

⚡ Quick Recall

Bile juice = Bilirubin + Biliverdin pigments → greenish-yellow colour. Bile stored in Gall bladder. Commonest gallstones = cholesterol. Calcium oxalate is associated with kidney stones.

🌬️ Aerobic vs Anaerobic Respiration

Feature	Aerobic	Anaerobic
O₂	Required	Not required
Oxidation	Complete	Partial breakdown
Energy	38 ATP (classic theoretical maximum; actual yield may be lower)	2 ATP net
Location	Cytoplasm + Mitochondria	Cytoplasm only
Products	CO₂ + H₂O	Ethanol + CO₂ (in yeast)
Occurs in	All autotrophic plants, most animals	Yeast, many bacteria, human muscles during exercise

Aerobic: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + 38 ATP (classic theoretical maximum)

Anaerobic: C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ + 2 ATP

⚠ Exam Trap

Aerobic = 38 ATP (classic theoretical maximum). Anaerobic = 2 ATP. Human muscles during exercise → Anaerobic. Yeast → Anaerobic (ethanol production — fermentation!).

🫁 Human Respiratory System

Nostrils: Air enters, mucus & hairs clean and moisten air
Pharynx: Common passage; epiglottis prevents food entry
Larynx: Sound production; Adam's apple in men
Trachea: 10–12 cm; Hyaline cartilage C-shaped rings
Bronchi: One pair for each lung
Lungs: One pair, pale pink, spongy
Right lung: Large, broad, 3 lobes, 3 bronchi
Left lung: Small, thin, 2 lobes, 2 bronchi
Alveoli: Balloon-shaped, single-layered — site of gaseous exchange

Inspiration (Breathing in)

O₂ = 21%, CO₂ = 0.03%
Diaphragm: Flattens downward

Exhalation (Breathing out)

O₂ = 16%, CO₂ = 4.4%
Diaphragm: Dome-shaped

⚡ Quick Recall — Gas Transport

O₂ transport: 97% by Haemoglobin
CO₂ transport: Bicarbonate 70% + Haemoglobin 23% + Plasma 7%

🐟 Respiratory Surfaces — Different Organisms

Organism	Respiratory Surface
Amoeba and Planaria	Cell membrane
Earthworm and Leech	Moist skin
Fish, Prawns, Tadpole	Gills
Frog	Moist skin + Lungs (both!)
Mosquito and Housefly	Trachea and Spiracles
Birds, Lizards, Terrestrial animals	Lungs

⚠ Exam Trap

Frog = Moist skin AND lungs (uses both). Insects such as mosquitoes = Trachea + Spiracles (no gills). Amoeba = Cell membrane (simplest).

🩸 Blood — Key Facts

pH 7.3–7.5

Alkaline

5–6 litres

In adults (7–8% body weight)

55% Plasma

Liquid part

45% Cells

Solid part

Feature	RBC (Erythrocytes)	WBC (Leucocytes)	Platelets (Thrombocytes)
Number/mm³	4.5–5 million	6,000–8,000	1,50,000–3,50,000
Shape	Biconcave, round	Round or irregular	Irregular, disc-like
Size	7–8 µm diameter	12–20 µm	2–3 µm
Lifespan	~120 days	Hours to months	8–10 days
Formation	Liver/Spleen (before birth), Bone marrow (after birth)	Bone marrow, lymph nodes, spleen, thymus, tonsils	Megakaryocytes of bone marrow
Function	O₂ & CO₂ transport	Immunity / Protection	Blood clot formation

WBC Types

Agranular: Lymphocytes (20–25%), Monocytes (2–10%)
Granular: Neutrophils (60–65%), Eosinophils (2–3%), Basophils (0.5–1%)

Blood Groups

A, B, O discovered by Landsteiner
AB discovered by Von de Castello & Sturli (1902)
O− = Universal red-cell donor (ABO + Rh)
AB+ = Universal red-cell recipient (ABO + Rh)
Rh factor: Discovered by Landsteiner & Wiener (1940) in Rhesus monkey
Rh⁺: 85% world, 97% India

⚠ Exam Trap

RBC lifespan = 120 days. Platelet lifespan = 8–10 days. Neutrophils = most abundant WBC (60–65%). Megakaryocytes → produce platelets. RBC "Graveyard" = Spleen.

❤️ Heart — Structure & Function

Four-chambered: 2 Atria + 2 Ventricles
Atria receive blood; Ventricles pump blood
Muscular, contractile, self-pumping organ
Covered by Double-walled Pericardium
Weight: Men = 280–340 gm | Women = 230–240 gm | Newborn = 20 gm

Valves

Tricuspid: Right atrium ↔ ventricle
Bicuspid (Mitral): Left atrium ↔ ventricle
Semilunar: Ventricle ↔ Artery

Heart Sounds

Lub: Closure of AV valve (1st sound)
Dup: Closure of Semilunar valve (2nd sound)

Heartbeat Stats

Rate: 72–75 beats/min
One cardiac cycle at 75 beats/min: 0.8 second
Cardiac output: 5 L/min
BP: Systolic 120 mmHg, Diastolic 80 mmHg
Pacemaker: SA Node

🔄 Blood Circulation Path

Right atrium: Receives deoxygenated blood via Vena cava
Right ventricle: Pumps to lungs via Pulmonary artery (deoxygenated)
Left atrium: Receives oxygenated blood from lungs via Pulmonary veins
Left ventricle: Pumps to body via Aorta (oxygenated)

⚠ Exam Trap

Pulmonary artery carries deoxygenated blood (heart → lungs). Pulmonary vein carries oxygenated blood (lungs → heart). This is a major exception.

⚡ Quick Recall — Blood Vessels

Arteries: Away from heart, oxygenated (except pulmonary), thick-walled, no valves
Veins: To heart, deoxygenated (except pulmonary), thin-walled, have valves
Capillaries: Connect arteries to veins, allow substance exchange
Varicose veins = dilated superficial veins due to incompetent venous valves (legs)

🌿 Excretion in Plants

Waste Type	Method of Excretion
Liquid waste	Excess water released by Transpiration through stomata
Gaseous waste	CO₂ and O₂ expelled through stomata and lenticles
Solid waste	Stored in cell vacuoles and dead cell tissues; removed by shedding leaves
Useful plant waste	Volatile oils, perfumes, gums, resins, natural rubber, tannin

🚽 Human Excretory System

Removes nitrogenous wastes (mainly Urea, produced in liver) as urine through kidneys

Bean-shaped

Kidney shape

10 lakh

Nephrons per kidney

Nephron

Structural & functional unit

pH 6.0

Urine pH

Excretory Organs

Kidneys: Main excretory organs (1 pair, bean-shaped)
Ureter: 1 pair, muscular tubes — kidney → bladder
Urinary bladder: Single muscular urine-collecting organ
Urethra: Single duct — urine removal (males: joint with semen)

Urine Facts

Colour: Yellow → Urochrome / Urobilin pigment
Composition: Water 95% + Urea 2%
pH = 6.0 (slightly acidic)
Common kidney stones: Calcium oxalate

🔬 Nephron Structure

Bowman's capsule (cup-like)
Proximal convoluted tubule
Henle's loop
Distal convoluted tubule
Collecting duct

⚡ Quick Recall — Nephron Path

Bowman's capsule → PCT → Henle's loop → DCT → Collecting duct → Ureter → Bladder → Urethra

🔀 Transportation in Plants

Water Transport

By Xylem
Unidirectional (upward)
Force: Cohesive & adhesive forces + Transpiration pull

Food Transport

By Phloem as sucrose sugar
Bidirectional / Multidirectional
Mass flow: Munch hypothesis
Phloem carries food up and down from leaves

⚗️ Chapter 06 — Biological Process