GCSE Combined Science: Cell Biology, Bioenergetics, Chemistry, and Energy

Practice flashcards covering key vocabulary and concepts from GCSE Cell Biology, Bioenergetics, Atomic Structure, Chemical Bonding, and Energy Transfer.

Differentiation

The process where a cell changes and becomes a specialised cell to perform a specific function.

Prokaryotic Cell

A cell, such as a bacterial cell, that does not have a true nucleus but instead has a single strand of DNA floating in the cytoplasm and may contain a plasmid.

Eukaryotic Cell

A type of cell, including plant and animal cells, that contains ribosomes, a cell membrane, cytoplasm, and a nucleus.

Osmosis

The movement of water molecules across a partially permeable membrane from a region of higher concentration to a region of lower concentration.

Active Transport

The movement of substances against a concentration gradient, a process that requires energy from respiration.

Mitosis

The stage of the cell cycle where DNA is replicated and the cell divides to create new, identical cells.

Embryonic Stem Cells

Undifferentiated cells that have the potential to turn into any kind of cell.

Alveoli

Specialised structures in the lungs where gas exchange takes place, featuring a large surface area, moist lining, thin walls, and a good blood supply.

Photosynthesis

An endothermic chemical reaction in plants that uses light energy to convert carbon dioxide and water into glucose and oxygen, represented by the equation $6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$.

Limiting Factor

An environmental condition such as temperature, light intensity, or carbon dioxide concentration that restricts the rate of photosynthesis.

Inverse Square Law

A law describing light intensity at different distances, stating that $\text{light intensity} \propto \frac{1}{\text{distance}^2}$. If distance is doubled, light intensity is reduced to one quarter.

Aerobic Respiration

An exothermic chemical reaction occurring in mitochondria that uses oxygen to release energy from glucose: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP}$.

Metabolism

The combination of all the chemical reactions that occur in a cell or in the body, such as the synthesis of new molecules via energy from respiration.

Oxygen Debt

The amount of oxygen required after vigorous exercise to convert built-up lactic acid back into glucose in the liver.

Isotope

An atom of the same element that has the same number of protons but a different number of neutrons, resulting in a different mass number.

Compound

A substance formed when two or more elements are chemically joined by bonds, making them difficult to separate.

Chromatography

A laboratory technique used to separate out mixtures of substances.

Fractional Distillation

A separation method used to separate a mixture of liquids based on their different boiling points, such as separating crude oil into fractions.

Alkali Metals

Group 1 elements that are soft and very reactive due to having one electron in their outer shell; reactivity increases as you go down the group.

Halogens

Group 7 non-metals where melting and boiling points increase as you go down the group, but reactivity decreases.

Ionic Bonding

A type of chemical bonding between a metal and a non-metal involving the electrostatic attraction between oppositely charged ions.

Covalent Bonding

The sharing of a pair of electrons between non-metal atoms to gain a full outer shell.

Graphene

A single layer of graphite that is very strong due to its covalent bonds and is capable of conducting electricity.

Nanoparticles

Structures that are between $1\,nm$ and $100\,nm$ in size, characterized by a very high surface area to volume ratio.

Specific Heat Capacity

The amount of energy needed to raise the temperature of $1\,kg$ of a material by $1\,^{\circ}C$, calculated using the equation $\Delta E = m \times c \times \Delta \theta$.

Power

The rate of transfer of energy or the amount of work done in a given time, calculated as $P = \frac{E}{t}$ and measured in Watts ($W$).

Efficiency

The ratio of useful output energy transfer to total input energy transfer, often expressed as $\text{efficiency} = \frac{\text{useful output energy transfer}}{\text{total input energy transfer}}$.

Conduction

The process of energy transfer in solids where heated particles vibrate and collide, passing energy to neighboring particles.