Key Terms: Cell Organelles
Part of Cell Organelles · GCSE GCSE Biology revision
This definitions covers Key Terms: Cell Organelles within Cell Organelles for GCSE Biology. Revise Cell Organelles in Cell Biology for GCSE Biology with 12 exam-style questions and 15 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 7 of 13 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 7 of 13
Practice
12 questions
Recall
15 flashcards
📖 Key Terms: Cell Organelles
- Organelle
- A specialised subunit within a cell that has a specific function, surrounded by its own membrane (in eukaryotic cells).
- Nucleus
- The control centre of the cell. Contains chromosomes made of DNA, which carry genetic information controlling cell activity. Surrounded by a double nuclear membrane with pores.
- Mitochondria
- The site of aerobic respiration. Mitochondria transfer energy from glucose and oxygen, producing ATP — the usable energy currency of the cell. They have their own DNA and ribosomes.
- Ribosome
- Tiny structures (not membrane-bound) found either free in the cytoplasm or attached to rough ER. They are the site of protein synthesis — reading mRNA to build proteins from amino acids.
- Endoplasmic Reticulum (ER)
- A network of membrane-bound tubes and sacs. Rough ER (studded with ribosomes) folds and processes proteins. Smooth ER makes lipids and detoxifies substances.
- Golgi Apparatus
- A stack of flattened membrane sacs that receives proteins from the ER, modifies them, packages them into vesicles, and sends them to their destination inside or outside the cell.
- Lysosome
- A membrane-bound organelle containing digestive enzymes. It breaks down old organelles, engulfed bacteria, and worn-out cell components.
- Chloroplast
- Found only in plant cells (and some algae). Contains chlorophyll, which absorbs light energy for photosynthesis. Has its own DNA and ribosomes. Surrounded by a double membrane.
Must Memorise: Mitochondria = site of aerobic respiration (energy release). Present in ALL eukaryotic cells.
Must Memorise: Ribosomes = site of protein synthesis. Found in ALL cells — even prokaryotic cells have them.
Must Memorise: Nucleus = controls all cell activities via DNA. Only in eukaryotic cells.