UEC Science Master Notes Vocabulary

Vocabulary practice flashcards defining foundational scientific terms across biodiversity, nutrition, water, acids, forces, heat, and sound waves.

Biodiversity

The variety of living organisms, which can be considered at the levels of genes, species, and ecosystems.

Excretion

The process of removing metabolic waste products produced by cells from an organism.

Egestion

The removal of undigested food from the digestive tract as faeces.

Binomial Nomenclature

A classification system that gives a species a two-part scientific name consisting of Genus + species.

Carbohydrates

A major class of food that serves as a primary energy source, including sugars and starch.

Proteins

Nutrients made from amino acids required for growth, repair, enzymes, hormones, antibodies, and structural components.

Mechanical Digestion

The breakdown of food that changes its physical size, such as through chewing or stomach churning.

Chemical Digestion

The breakdown of large, insoluble food molecules into smaller, soluble molecules using digestive enzymes.

Bile

A fluid produced by the liver and stored in the gall bladder that neutralises acidic chyme and emulsifies fats to increase surface area for lipase.

Villi

Folds and finger-like projections in the small intestine that provide a large surface area for absorbing digested nutrients.

Solution

A homogeneous mixture formed when a solute is dissolved in a solvent.

Solubility

The maximum amount of solute that can dissolve in a specified amount of solvent at specified conditions, such as temperature and pressure.

Saturated Solution

A solution that contains the maximum amount of dissolved solute possible under current conditions, leaving extra solute undissolved.

Acid

A substance that produces hydrogen ions ($H^+$) in aqueous solution and has a pH below $7$.

Alkali

A base that dissolves in water to produce hydroxide ions ($OH^-$), generally having a pH above $7$.

Strong Acid

An acid that ionises essentially completely in water, such as hydrochloric acid ($HCl$).

Weak Acid

An acid that ionises only partially in water, such as ethanoic acid.

Neutralisation

The chemical reaction between an acid and an alkali to form a salt and water, with ionic equation $H^+ + OH^- \rightarrow H_2O$.

Speed

The distance travelled per unit time, calculated as $\text{speed} = \frac{\text{distance}}{\text{time}}$.

Velocity

Speed measured in a specified direction.

Acceleration

The rate of change of velocity, calculated as $a = \frac{v - u}{t}$.

Resultant Force

The single overall force acting on an object obtained by combining all individual acting forces.

Friction

A contact force that opposes relative motion or attempted motion between surfaces.

Weight

The gravitational force acting on a mass, measured in newtons ($N$) and calculated using $W = mg$.

Temperature

A measure of how hot or cold an object is, which relates to the average kinetic energy of its particles.

Heat

Thermal energy transferred spontaneously from a higher temperature region to a lower temperature region.

Conduction

The transfer of thermal energy through a material by direct interactions between particles.

Convection

The transfer of thermal energy in fluids through the bulk movement of heated regions expanding, becoming less dense, and rising.

Thermal Radiation

Electromagnetic energy (especially infrared) transfer that does not require a medium and can travel through a vacuum.

Thermal Equilibrium

The state where two objects in thermal contact reach equal temperatures and net heat transfer ceases.

Amplitude

The maximum displacement of a wave from its equilibrium position, which determines perceived sound loudness.

Frequency

The number of complete wave cycles per second, measured in hertz ($Hz$), which determines pitch.

Ultrasound

Sound waves with a frequency above the normal human hearing range, commonly greater than $20000_Hz$ ($20_kHz$).

Echo

A reflected sound wave that is heard separately from the original sound.