Life Processes Lecture Vocabulary

A comprehensive set of vocabulary flashcards covering core terms and definitions from the ‘Life Processes’ lecture, including nutrition, respiration, transport and excretion in both plants and animals.

Life Processes

Basic biological functions—nutrition, respiration, transportation and excretion—needed to maintain life in an organism.

Nutrition

Process of obtaining and utilising food for growth, energy and repair.

Respiration

Chemical breakdown of food molecules to release energy in the form of ATP inside cells.

Transportation

Transfer of substances such as gases, nutrients and wastes from one part of the body to another.

Excretion

Removal of harmful metabolic waste products from the body.

Autotrophic Nutrition

Mode of nutrition in which organisms (e.g., green plants) synthesise their own food from inorganic substances.

Heterotrophic Nutrition

Mode of nutrition in which organisms obtain ready-made organic food from other organisms.

Holozoic Nutrition

Ingestion, internal digestion and absorption of complex food substances, as in humans.

Saprophytic Nutrition

Feeding on dead and decaying organic matter, e.g., fungi.

Parasitic Nutrition

Deriving nutrition from a living host, often harming it, e.g., tapeworm.

Photosynthesis

Process by which green plants make glucose from CO₂ and H₂O using sunlight and chlorophyll, releasing O₂.

Conditions for Photosynthesis

Sunlight, chlorophyll, carbon dioxide and water must be present.

Chloroplast

Green cell organelle that houses chlorophyll and is the site of photosynthesis.

Chlorophyll

Green pigment that absorbs light energy for photosynthesis.

Stomata

Tiny pores on leaf surfaces that regulate gas exchange and water loss.

Variegated Leaf Experiment

Lab activity showing starch develops only in green areas, proving chlorophyll’s role in photosynthesis.

KOH

Potassium hydroxide; absorbs CO₂ in experiments demonstrating its necessity for photosynthesis.

Glucose (Plant Food)

Simple sugar produced in photosynthesis; stored as starch in plants.

Starch

Storage form of carbohydrates in plants, detected by iodine turning blue-black.

Glycogen

Storage form of carbohydrates in animals.

Pseudopodia

Temporary finger-like extensions of an Amoeba used for movement and capturing food.

Food Vacuole

Membrane sac in unicellular organisms where ingested food is digested.

Amoeba Nutrition

Holozoic feeding using pseudopodia to engulf food, digest in vacuoles, absorb and egest residues.

Cilia

Hair-like structures on Paramecium that sweep food toward a specific oral spot.

Paramecium Nutrition

Holozoic feeding where ciliary action directs food into a fixed oral groove for digestion.

Alimentary Canal

Continuous digestive tube from mouth to anus in humans.

Salivary Glands

Glands in the mouth secreting saliva containing the enzyme salivary amylase.

Salivary Amylase

Enzyme that converts starch to maltose (simple sugars) in the mouth.

Peristaltic Movement

Rhythmic contraction and relaxation of oesophageal walls pushing food to the stomach.

Stomach

Muscular organ secreting gastric juice for protein digestion and food storage.

Hydrochloric Acid

Acid in gastric juice providing acidic pH for pepsin action and killing microbes.

Pepsin

Protein-digesting enzyme active in the acidic environment of the stomach.

Mucus (Stomach)

Protective secretion that coats the stomach lining against acid corrosion.

Liver

Largest gland producing bile, detoxifying blood and storing glycogen.

Bile Juice

Alkaline fluid stored in the gallbladder that emulsifies fats and neutralises stomach acid.

Emulsification of Fats

Breakdown of large fat globules into tiny droplets by bile, aiding lipase action.

Gallbladder

Sac-like organ storing bile produced by the liver.

Pancreas

Gland secreting digestive enzymes (trypsin, lipase, amylase) and hormones like insulin.

Pancreatic Juice

Alkaline secretion containing enzymes for digestion of proteins, fats and carbohydrates.

Trypsin

Pancreatic enzyme that digests proteins into peptides in the small intestine.

Lipase

Enzyme that hydrolyses emulsified fats into fatty acids and glycerol.

Small Intestine

Longest part of alimentary canal where complete digestion and absorption occur.

Villi

Finger-like projections in the small intestine that increase surface area for nutrient absorption.

Large Intestine

Part of gut that absorbs water from undigested food and forms faeces.

Anal Sphincter

Muscular ring regulating the elimination of faeces through the anus.

Herbivore Intestine Length

Longer small intestine to allow cellulose digestion.

Carnivore Intestine Length

Shorter small intestine because animal proteins are easier to digest.

Breathing

Physical process of inhalation and exhalation; no energy released.

Aerobic Respiration

Complete oxidation of glucose using oxygen, producing CO₂, H₂O and lots of ATP.

Anaerobic Respiration

Incomplete breakdown of glucose without oxygen, producing less ATP and end products like ethanol or lactic acid.

Alcoholic Fermentation

Anaerobic conversion of glucose into ethanol, CO₂ and energy by yeast.

Lactic Acid Fermentation

Anaerobic conversion of glucose to lactic acid and energy in muscle cells, causing cramps.

ATP

Adenosine triphosphate; the energy currency of the cell.

Diaphragm

Dome-shaped muscle separating thoracic and abdominal cavities; key in breathing movements.

Residual Volume

Air remaining in lungs after exhalation to ensure continuous gas exchange.

Trachea

Windpipe conducting air to bronchi; kept open by cartilaginous rings.

Cartilaginous Rings

C-shaped cartilage in trachea preventing airway collapse.

Bronchi

Two main branches of trachea leading to each lung.

Bronchioles

Smaller subdivisions of bronchi within lungs ending at alveoli.

Alveoli

Microscopic air sacs where oxygen and carbon dioxide are exchanged with blood.

Root Pressure

Upward push of water in xylem generated by active ion uptake in roots.

Transpiration

Loss of water vapour from aerial parts of plants, creating transpirational pull.

Translocation

Transport of food (sucrose) from leaves to other plant parts via phloem.

Xylem

Plant tissue conducting water and minerals upward from roots; flow is unidirectional.

Phloem

Plant tissue transporting organic nutrients bidirectionally between source and sink.

Heart

Muscular organ pumping blood throughout the body via rhythmic contractions.

Atria

Upper heart chambers receiving blood from veins.

Ventricles

Lower heart chambers pumping blood into arteries; walls thicker than atria.

Aorta

Largest artery carrying oxygenated blood from left ventricle to the body.

Vena Cava

Largest vein returning deoxygenated blood to the right atrium.

Pulmonary Artery

Artery carrying deoxygenated blood from right ventricle to the lungs.

Pulmonary Vein

Vein carrying oxygenated blood from lungs to left atrium.

Arteries

Thick-walled vessels transporting blood away from the heart under high pressure; no valves.

Veins

Thin-walled vessels returning blood to the heart; contain valves to prevent backflow.

Capillaries

Microscopic vessels with one-cell-thick walls enabling exchange of substances between blood and tissues.

Double Circulation

Blood passes twice through the heart in one complete cycle, ensuring separation of oxygenated and deoxygenated blood.

Plasma

Straw-coloured fluid of blood transporting nutrients, CO₂ and wastes.

Red Blood Cells

Biconcave cells containing haemoglobin; transport oxygen.

White Blood Cells

Blood cells that defend the body against infection and produce antibodies.

Platelets

Cell fragments that initiate blood clotting to prevent excessive bleeding.

Lymph

Colourless tissue fluid draining into lymphatic vessels; returns excess fluid and absorbs fats.

Nephron

Structural and functional unit of the kidney that forms urine.

Glomerulus

Ball of capillaries in each nephron where blood filtration occurs.

Bowman's Capsule

Cup-shaped structure surrounding the glomerulus; receives the filtrate.

Selective Reabsorption

Process in nephron tubules retaining useful substances like glucose, amino acids and most water.

Tubular Secretion

Active transport of additional wastes and ions from blood into nephron filtrate.

Ureters

Tubes carrying urine from kidneys to urinary bladder.

Urinary Bladder

Muscular sac that stores urine; under nervous control.

Urethra

Channel through which urine is expelled from the body.

Dialysis

Artificial filtration of blood to remove wastes in kidney failure patients.

Dialysing Fluid

Solution used in dialysis with same osmotic pressure as blood but without nitrogenous wastes.

Excretion in Plants

Waste removal via diffusion of gases, transpiration of water and shedding of leaves or secreting into soil.