Key Concepts in Biology, Chemistry, and Physics

Function of mitochondria

They release energy through respiration.

Osmosis

The diffusion of water through a partially permeable membrane.

Role of ribosomes

They make proteins by joining amino acids.

Mitosis

The cell divides to form two identical daughter cells.

Function of enzymes in digestion

They speed up the breakdown of food molecules.

Function of the arteries

They carry blood away from the heart under high pressure.

Coronary heart disease

Blockage of the coronary arteries by fatty deposits.

Xylem and phloem

Xylem transports water; phloem transports food in plants.

Relative charge of a proton

1

Mass number of an atom

The total number of protons and neutrons.

Ionic bonding

Electrons are transferred from metals to non-metals.

First periodic table developer

Dmitri Mendeleev.

Structure of diamonds

Giant covalent structure.

Ionic compounds conduct electricity when molten

Because ions are free to move and carry charge.

Polymer

A long chain of repeating monomers.

Malleability of metals

Layers of atoms can slide over each other.

Equation for kinetic energy

KE = 0.5 × mass × speed²

Specific heat capacity

The energy needed to raise the temperature of 1kg of a substance by 1°C.

Renewable energy sources

Sources that will never run out, e.g. wind, solar, hydro.

Reduces unwanted energy transfer

Insulation, lubrication, and streamlining.

Substance changes state

The particles rearrange, but the mass stays the same.

Equation for density

Density = Mass ÷ Volume.

Gas pressure

Particles colliding with the walls of a container.

Gas pressure with increased temperature

It increases.

Isotope

Atoms of the same element with different numbers of neutrons.

Types of nuclear radiation

Alpha, beta, and gamma.

Half-life

Time it takes for the activity of a radioactive substance to halve.

Dangers of ionising radiation

It can damage cells and cause cancer.