Year 9 Biology Revision Notes

A set of flashcards covering key vocabulary and definitions from Year 9 Biology notes on the variety of life and biological molecules.

Prokaryotes

Simple cells without a nucleus, with circular DNA, that may have cell walls and membranes.

Eukaryotic Organisms

Organisms with complex cells that contain a nucleus, including plants, animals, fungi, and protists.

Cellulose

A carbohydrate that forms the cell wall in plants.

Chloroplasts

Organelles where photosynthesis occurs, found in plant cells.

Mycelium

A network of hyphae that forms the body of fungi.

Pathogens

Microorganisms that cause disease, including bacteria, viruses, fungi, and protoctists.

Enzyme

Biological catalysts that speed up chemical reactions in living organisms.

Optimum temperature

The temperature at which an enzyme operates most efficiently.

Denaturation

A process where an enzyme loses its functional shape, often due to extreme temperature or pH changes.

Active Site

The region of an enzyme where the substrate binds to undergo a chemical reaction.

Lock and Key Theory

A model that explains how enzymes and substrates fit together, like a key fits into a lock.

Photosynthesis

The process by which green plants use sunlight to synthesize foods from carbon dioxide and water.

Amoeba

A type of single-celled organism that can move and feed like an animal.

Chlamydomonas

A single-celled green algae that has two flagella and is capable of photosynthesis.

Extracellular Digestion

A process by which fungi break down food outside their cells and then absorb the nutrients.

Chitin

A component of the cell wall in fungi, providing structural support.