This definitions covers Key Definitions within Cell Structure for GCSE Biology. Cell theory, prokaryotic and eukaryotic cells, animal and plant cell organelles, bacterial cells, specialized cells, and microscopy It is section 8 of 17 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 8 of 17
Practice
20 questions
Recall
25 flashcards
📖 Key Definitions
Cell: The basic structural and functional unit of all living organisms. Every living thing is made of one or more cells.
Nucleus: A membrane-bound organelle found in eukaryotic cells that contains the cell's genetic material (DNA) and controls all cell activities.
Mitochondria (singular: mitochondrion): Membrane-bound organelles that are the site of aerobic respiration, releasing energy in the form of ATP for the cell to use.
Organelle: A specialised structure within a cell that carries out a specific function, often (in eukaryotes) enclosed by its own membrane.
Cytoplasm: The jelly-like fluid that fills the cell and surrounds the organelles. Many chemical reactions take place here.
Cell membrane: The thin, flexible layer surrounding all cells that controls the movement of substances into and out of the cell. It is selectively permeable.
Ribosome: A tiny organelle found in all cells (prokaryotic and eukaryotic) that is the site of protein synthesis.
Chromosome: A long, coiled molecule of DNA found in the nucleus of eukaryotic cells. Humans have 46 chromosomes (23 pairs) in most body cells.
DNA (Deoxyribonucleic acid): The molecule that carries genetic information. It is found in the nucleus of eukaryotic cells and free in the cytoplasm of prokaryotic cells.