cell membrane
B2Formal, Academic, Scientific
Definition
Meaning
A thin, semi-permeable biological structure that surrounds a cell, separating its interior from the external environment, regulating what enters and leaves.
In a broader or metaphorical sense, can refer to any selectively permeable barrier or boundary, especially in technological or conceptual contexts.
Linguistics
Semantic Notes
A core concept in biology. Often discussed in terms of structure (lipid bilayer), function (selective permeability), and components (proteins, cholesterol). Implies both a boundary and a dynamic, active interface.
Dialectal Variation
British vs American Usage
Differences
No significant lexical differences. Spelling follows national conventions (e.g., 'behaviour' of molecules UK vs. 'behavior' US). Conceptual emphasis identical.
Connotations
Purely technical and neutral in both varieties.
Frequency
Equally common in academic and scientific contexts in both regions.
Vocabulary
Collocations
Grammar
Valency Patterns
The cell membrane [verbs: surrounds, protects, regulates] the cell.Substances [verbs: cross, penetrate, diffuse through] the cell membrane.The cell membrane is composed of [nouns: lipids, proteins].Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Usage
Context Usage
Business
Rare. Potentially in metaphorical use for company boundaries or IT security perimeters.
Academic
Primary context. Core term in biology, biochemistry, medicine, and related life sciences.
Everyday
Limited. Generally only in educational contexts or popular science discussions.
Technical
Ubiquitous. Precise term for the specific biological structure.
Examples
By Part of Speech
adjective
British English
- The membrane-bound organelle.
- Membrane-associated proteins.
American English
- The membrane-bound organelle.
- Membrane-associated proteins.
Examples
By CEFR Level
- Every cell has a cell membrane.
- The cell membrane is like a bag.
- Water can pass through the cell membrane easily.
- The cell membrane controls what goes into the cell.
- The fluidity of the cell membrane is crucial for its function.
- Cholesterol molecules are embedded within the cell membrane to stabilise it.
- The receptor protein embedded in the cell membrane initiated a cascade of intracellular signals.
- The integrity of the plasma membrane was compromised by the cytolytic toxin.
Learning
Memory Aids
Mnemonic
Think of a 'membrane' as a 'brain' for the cell's border - it decides what's 'in' and what's 'out'.
Conceptual Metaphor
A SECURITY GATE / FILTER / SKIN. It is both a protective barrier and a sophisticated control point.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid direct calque 'клеточная мембрана' as the only term; 'плазматическая мембрана' (plazmaticheskaya membrana) is also correct and often used interchangeably in scientific Russian.
- Do not confuse with 'cell wall' ('клеточная стенка'), which is a rigid outer layer in plant, fungal, and bacterial cells.
Common Mistakes
- Misspelling as 'cell membrain' or 'cell membrance'.
- Using 'cell wall' synonymously for all cells (only correct for plants, bacteria, fungi).
- Incorrect article use: 'a cell membrane' (referring to any instance) vs. 'the cell membrane' (referring to the concept).
Practice
Quiz
What is the primary function of the cell membrane?
FAQ
Frequently Asked Questions
Yes, in most contexts, 'cell membrane' and 'plasma membrane' are synonymous, referring to the outer membrane of the cell. 'Plasma membrane' is sometimes preferred in technical writing.
Not clearly. The cell membrane is extremely thin (about 7-10 nanometres). Its boundary might be inferred, but its detailed structure requires an electron microscope.
It is primarily composed of a double layer of lipids (the lipid bilayer), with various proteins embedded in or attached to it. Carbohydrates may also be attached to lipids or proteins on the outer surface.
Yes, a cell membrane is a universal feature of all living cells, from bacteria to plants and animals. It is a fundamental requirement for life as it defines the cell's boundary.