G1 Science Definitions
Key terms across K123 integrated Science: energy, circuits, waves, forces, food, digestion, breathing, circulation and practical skills.
On this page
A glossary for G1 integrated Science (K123, 2027) across all three course contexts. Start with a meaning, then use the distinction to explain a real situation.
Cover a meaning and explain it in your own words. Check that you kept the key distinction; longer wording is not automatically more precise.
Machines Around Us: energy and electricity
| Term | Meaning | Remember |
|---|---|---|
| Energy | Quantity transferred when changes occur, such as heating or movement. | Measured in J; account for energy transferred to the surroundings. |
| Kinetic energy | Energy an object has because it is moving. | Do not confuse energy with speed. |
| Gravitational potential energy | Energy associated with position in a gravitational field. | Raising an object transfers energy to this store. |
| Elastic potential energy | Energy stored when an elastic object is stretched or compressed. | Examples include springs and elastic bands. |
| Chemical potential energy | Energy associated with the chemical arrangement of a substance. | Fuels and food can release energy during reactions. |
| Conservation of energy | Energy cannot be created or destroyed; it is transferred or converted between forms. | “Wasted” energy is transferred in less useful ways, not destroyed. |
| Power | Energy transferred per unit time. | Unit W; a higher power appliance transfers energy faster. |
| Current | Rate of flow of electric charge. | Unit A; measured by an ammeter in series. |
| Voltage | Energy transferred per unit charge between two points. | Unit V; measured by a voltmeter across a component. |
| Resistance | Measure of how strongly a component opposes current. | Compare circuits at the same voltage. |
| Series circuit | Circuit with one path through the connected components. | Current is the same throughout. |
| Parallel circuit | Circuit with separate branches connected between the same two points. | Voltage is the same across the branches. |
| Power rating | Power an appliance is designed to use at its rated voltage. | It is not the total energy used over a day. |
| Voltage rating | Voltage at which an appliance is designed to operate. | Match the appliance to a suitable supply. |
| Step-up / step-down transformer | Device that increases / decreases voltage in electricity supply systems. | High-voltage transmission reduces cable energy loss. |
Machines Around Us: waves and forces
| Term | Meaning | Remember |
|---|---|---|
| Wave | A disturbance that transfers energy. | A vibration can generate waves in a rope or spring. |
| Amplitude | Greatest displacement from the resting position. | Compare it from the middle position, not crest to trough. |
| Frequency | Number of complete vibrations each second. | Unit Hz. |
| Wavelength | Distance between equivalent positions on successive waves, such as consecutive crests. | Unit m; select consecutive matching points. |
| Force | Push or pull that can change shape, speed or direction, or produce a turning effect. | An object can experience several forces at once. |
| Speed | Distance travelled per unit time. | Use total distance and total time for average speed. |
| Acceleration | Change in speed per unit time for motion in one direction. | Constant speed means zero acceleration in this one-direction model. |
| Moment of a force | Turning effect of a force about a pivot. | Greater force or greater perpendicular distance gives a greater turning effect; no moment equation is required. |
Food Matters
| Term | Meaning | Remember |
|---|---|---|
| Photosynthesis | Process in which green plants use light energy to make food from carbon dioxide and water, releasing oxygen. | Chlorophyll absorbs light; fertiliser is not the plant’s food. |
| Food chain | Sequence showing feeding relationships and transfer of energy between organisms. | Arrows point from food to the organism consuming it. |
| Food web | Network of connected food chains. | An organism may have more than one food source. |
| Producer | Organism that makes its own food, commonly by photosynthesis. | Green plants begin many food chains. |
| Consumer | Organism that obtains food by feeding on other organisms. | A herbivore eats plants; a carnivore eats animals. |
| Decomposer | Organism that breaks down dead material and waste. | Returns nutrients to the environment. |
| Carbohydrate | Nutrient used mainly as an energy source. | Sugars and starch are examples. |
| Protein | Nutrient needed for growth and repair of tissues. | Protein can also be used as an energy source. |
| Fat | Nutrient that supplies energy and helps with insulation and energy storage. | A balanced diet needs suitable amounts, not complete avoidance. |
| Vitamin / mineral | Nutrient required in small amounts for healthy body functioning. | Deficiency can affect health; “small amount” does not mean unimportant. |
| Acid / alkali | Substance with acidic / alkaline properties in water. | pH below 7 is acidic; above 7 is alkaline at room temperature. |
| Neutralisation | Reaction between an acid and an alkali to produce salt and water. | It is a chemical reaction, not just dilution. |
| Food spoilage | Changes that make food unsuitable to eat, often through microbial activity. | Unsafe food does not always look or smell spoiled. |
| Food preservation | Treatment that slows processes causing food to spoil. | Cooling slows microbial growth; it does not reliably kill every microbe. |
| Cross-contamination | Transfer of harmful microorganisms from one food or surface to another. | Keep raw and ready-to-eat foods and utensils separate. |
Our Body and Health
| Term | Meaning | Remember |
|---|---|---|
| Balanced diet | Diet supplying suitable amounts of energy and nutrients for a person’s needs. | Needs vary with age and activity. |
| Digestion | Breakdown of large food molecules into smaller, soluble molecules that can be absorbed. | Breakdown and absorption are different processes. |
| Mechanical digestion | Physical breakdown of food into smaller pieces. | Chewing increases surface area without changing the food molecules. |
| Chemical digestion | Breakdown of food molecules by chemical reactions involving enzymes. | Produces smaller molecules. |
| Enzyme | Biological catalyst that speeds up a chemical reaction without being used up by it. | Its activity depends on conditions such as temperature and pH. |
| Absorption | Movement of digested nutrients through the intestinal wall into transport systems. | Mainly occurs in the small intestine. |
| Egestion | Removal of undigested material as faeces. | Different from removing waste made by body cells. |
| Breathing | Movement of air into and out of the lungs. | Not the same as cellular respiration. |
| Gas exchange | Movement of oxygen and carbon dioxide between air in the lungs and the blood. | Gases move across the alveolar walls. |
| Respiration | Chemical reactions in cells that release energy from food. | Aerobic respiration uses oxygen; it happens in cells, not only in lungs. |
| Artery | Blood vessel carrying blood away from the heart. | The direction defines it, not the oxygen content. |
| Vein | Blood vessel carrying blood towards the heart. | The pulmonary vein carries oxygenated blood. |
| Capillary | Very small blood vessel with a thin wall allowing exchange with tissues. | Links the arterial and venous sides of circulation. |
| Plasma | Liquid part of blood that carries cells and dissolved substances. | Carries nutrients, hormones and carbon dioxide among other substances. |
| Red blood cell | Blood cell containing haemoglobin that transports oxygen. | Its main job differs from a white blood cell’s defence role. |
| White blood cell | Blood cell involved in defence against pathogens. | Different types have different defence functions. |
| Platelet | Small blood component involved in clotting. | Helps prevent blood loss at a damaged vessel. |
| Pathogen | Agent capable of causing disease, such as a harmful bacterium or virus. | Not all microorganisms cause disease. |
Working scientifically
| Term | Meaning | Remember |
|---|---|---|
| Independent variable | Quantity deliberately changed in an investigation. | Change one relevant factor at a time in a fair test. |
| Dependent variable | Quantity observed or measured in response. | State what you measure and its unit where appropriate. |
| Control variable | Quantity kept constant for a fair comparison. | Explain how it is kept constant. |
| Observation | Information obtained by senses or measurements. | Separate what you observe from an explanation of why it happened. |
| Conclusion | Statement answering the investigation question using evidence. | A conclusion should follow from the results. |
Try a comparison
Is an artery always a vessel carrying oxygenated blood? No. An artery carries blood away from the heart. The pulmonary artery carries deoxygenated blood towards the lungs. Direction is the defining feature.
Open the G1 course hub for the lessons and topic checks across the integrated course.