applied science

What is diffusion?

Movement of particles from high to low concentration until evenly spread.

What is osmosis?

Movement of water from high to low water concentration through a partially permeable membrane.

What is active transport?

Movement of particles against the concentration gradient using energy (ATP).

What are enzymes and how do they work?

Biological catalysts that speed up reactions by having an active site that fits a specific substrate.

What is aerobic respiration?

Glucose + oxygen → carbon dioxide + water + energy.

What is DNA made of?

A double helix made of nucleotides containing sugar, phosphate, and a base.

Define atom, element, compound.

Atom = smallest particle. Element = one type of atom. Compound = atoms chemically bonded.

What is an ion?

A charged particle formed by loss or gain of electrons.

What is pH?

A scale showing acidity/alkalinity. Acid < 7, neutral = 7, alkali > 7.

What happens when a solid melts?

Particles gain energy, move faster, break forces, become liquid.

Why is mass conserved in reactions?

Atoms are rearranged, not created or destroyed.

Name energy stores.

Kinetic, thermal, chemical, gravitational, elastic, nuclear.

What is a force?

A push or pull that can change speed, shape, or direction.

How do you calculate speed?

Speed = distance ÷ time.

What is current?

Flow of charge in a circuit.

Difference between series and parallel circuits?

Series = one loop, current same. Parallel = branches, current splits.

What are variables?

Independent = changed. Dependent = measured. Control = kept the same.

Difference between accuracy and precision?

Accuracy = closeness to true value. Precision = repeatability.

How to improve an experiment?

Repeat tests, control variables, use precise equipment.

What is a risk assessment?

Identifying hazards and how to reduce them.