Cambridge IGCSE Biology 0610 – Core & Supplement Vocabulary

Vocabulary flashcards summarising essential Cambridge IGCSE Biology 0610 syllabus terms for Movement, Biological Molecules, Enzymes, Plant & Human Nutrition, Transport, Immunity, Gas Exchange, Respiration and Excretion.

Diffusion

Net movement of particles from higher to lower concentration down a concentration gradient due to random kinetic energy.

Kinetic energy (in diffusion)

The inherent energy of random molecular movement that drives diffusion without extra energy input.

Cell membrane (role in diffusion)

Partially permeable barrier through which certain substances move into and out of cells by diffusion.

Surface area (diffusion factor)

Larger exposed area speeds diffusion by allowing more particles to cross at once.

Temperature (diffusion factor)

Higher temperature increases kinetic energy, raising diffusion rate.

Concentration gradient

Difference in concentration between two regions; steeper gradients speed diffusion.

Distance (diffusion factor)

Shorter diffusion path increases diffusion rate.

Osmosis

Net movement of water molecules from higher water potential (dilute) to lower water potential (concentrated) through a partially permeable membrane.

Water potential

Measure of free-energy of water; determines the direction of osmosis.

Turgid cell

Plant cell swollen with water; cytoplasm pushes against the wall creating turgor pressure.

Plasmolysis

Condition when plant cytoplasm pulls away from cell wall after water loss in strong solution.

Flaccid cell

Plant cell that has lost water and is limp, but not fully plasmolysed.

Active transport

Energy-requiring movement of particles through a membrane from lower to higher concentration against the gradient.

Protein carrier

Membrane protein that uses energy from respiration to pump molecules/ions during active transport.

Root hair ion uptake

Example of active transport where minerals move into plant roots against gradient.

Carbohydrate elements

Made of carbon, hydrogen and oxygen.

Protein elements

Made of carbon, hydrogen, oxygen, nitrogen (and sometimes sulfur).

Fat (lipid) elements

Composed of carbon, hydrogen and oxygen, proportionally more hydrogen and less oxygen than carbohydrates.

Polymer

Large molecule formed when many smaller sub-units (monomers) join together.

Starch

Storage polysaccharide of glucose in plants.

Glycogen

Storage polysaccharide of glucose in animals.

Cellulose

Structural polysaccharide forming plant cell walls.

Iodine test

Turns blue-black in presence of starch.

Benedict’s test

Brick-red precipitate indicates reducing sugars after heating.

Biuret test

Purple color indicates proteins.

Ethanol emulsion test

Turns cloudy white if fats or oils are present.

DCPIP test

Blue solution decolourises if vitamin C is present.

DNA double helix

Two antiparallel strands coiled; bases pair A–T and C–G holding strands together.

Catalyst

Substance that increases reaction rate and is unchanged at the end.

Enzyme

Protein acting as a biological catalyst in metabolic reactions.

Active site

Region of enzyme whose shape is complementary to its substrate.

Enzyme-substrate complex

Temporary binding of substrate in enzyme active site before products form.

Denaturation (enzyme)

Irreversible change in enzyme shape so substrate no longer fits; often due to extreme temperature or pH.

Optimum temperature

Temperature at which an enzyme’s activity is highest.

Photosynthesis

Process by which plants use light energy to convert CO2 and water into glucose and oxygen.

Chlorophyll

Green pigment in chloroplasts that traps light energy for photosynthesis.

Balanced equation (photosynthesis)

6CO2 + 6H2O → C6H12O6 + 6O2.

Starch (plant use)

Insoluble carbohydrate storage product of photosynthesis.

Cellulose (plant use)

Polysaccharide formed from glucose to build cell walls.

Sucrose

Transport form of carbohydrate in phloem sap.

Nitrate ions

Mineral ions required for amino acid and protein synthesis.

Magnesium ions

Mineral ions needed to make chlorophyll.

Limiting factor (photosynthesis)

Environmental condition (light, CO2, temperature) that restricts photosynthetic rate when in short supply.

Leaf cuticle

Waxy, non-cellular layer that reduces water loss.

Palisade mesophyll

Leaf tissue with many chloroplasts for maximum light absorption.

Spongy mesophyll

Leaf tissue with air spaces for gas exchange.

Stomata

Pores in epidermis that allow gas exchange and transpiration.

Balanced diet

Diet containing all nutrients in correct proportions for health.

Scurvy

Disease caused by vitamin C deficiency.

Rickets

Bone-softening disease from vitamin D or calcium deficiency.

Alimentary canal

Continuous digestive tube from mouth to anus.

Ingestion

Taking food and drink into the body.

Digestion

Breakdown of food; includes physical and chemical processes.

Absorption

Movement of digested nutrients from gut into blood or lymph.

Assimilation

Utilization of absorbed nutrients by body cells.

Egestion

Removal of undigested food as faeces.

Physical digestion

Mechanical breakdown of food without chemical change.

Incisor

Chisel-shaped tooth for cutting.

Canine

Pointed tooth for tearing.

Premolar

Tooth with flat surface for grinding.

Molar

Large tooth at back for grinding and chewing.

Enamel

Hard, outer protective layer of tooth.

Dentine

Bone-like tissue beneath enamel.

Pulp cavity

Central region of tooth containing nerves and blood vessels.

Bile

Alkaline fluid from liver that emulsifies fats to increase surface area for lipase.

Chemical digestion

Enzyme-catalysed breakdown of large insoluble molecules into small soluble ones.

Amylase

Enzyme converting starch to simple reducing sugars (maltose).

Protease

Enzyme that breaks proteins into amino acids.

Lipase

Enzyme splitting fats and oils into fatty acids and glycerol.

Hydrochloric acid (stomach)

Kills microbes and creates acidic pH for pepsin activity.

Maltase

Enzyme on intestinal epithelium that converts maltose to glucose.

Pepsin

Protease active in acidic stomach conditions.

Trypsin

Protease active in alkaline small intestine.

Villus

Finger-like projection of intestine that increases absorption surface area.

Microvilli

Microscopic folds on villus cells, further enlarging surface area.

Lacteal

Lymphatic vessel in villus absorbing fats.

Capillary network (villus)

Blood vessels absorbing glucose, amino acids, water, ions and vitamins from intestine.

Circulatory system

System of blood vessels with a pump (heart) and valves ensuring one-way flow.

Single circulation

Blood passes through the heart once per complete body circuit (e.g., fish).

Double circulation

Blood passes through the heart twice per circuit: pulmonary and systemic loops (mammals).

Coronary artery

Blood vessel supplying heart muscle with oxygenated blood.

Coronary heart disease

Condition where coronary arteries are blocked/narrowed, reducing blood to heart muscle.

Atrioventricular valves

Heart valves between atria and ventricles preventing backflow into atria.

Semilunar valves

Valves at exits of ventricles preventing backflow from arteries.

Artery

Thick-walled vessel carrying blood away from heart under high pressure.

Vein

Thin-walled vessel with valves carrying blood toward heart under low pressure.

Capillary

Microscopic vessel with one-cell-thick wall enabling exchange of substances with tissues.

Red blood cell

Biconcave cell with haemoglobin for oxygen transport.

White blood cell

Immune cell involved in phagocytosis or antibody production.

Platelet

Cell fragment that helps blood clot.

Plasma

Liquid portion of blood transporting cells, nutrients, hormones, ions and wastes.

Fibrin

Insoluble protein forming mesh in blood clot.

Pathogen

Disease-causing organism.

Transmissible disease

Disease whose pathogen can pass from one host to another.

Active immunity

Long-term defence produced by body’s own antibody production after infection or vaccination.

Passive immunity

Short-term defence by antibodies acquired from another individual (e.g., placenta, breast milk).

Antigen

Molecule on pathogen surface that triggers immune response.

Antibody

Protein produced by lymphocytes that binds specifically to antigens.

Vaccination

Introduction of weakened pathogens/antigens to stimulate active immunity.

Memory cell

Long-lived lymphocyte that responds quickly upon re-exposure to antigen.