endonuclease: meaning, definition, pronunciation and examples

Very low frequency
UK/ˌɛndəʊˈnjuːklɪeɪz/US/ˌɛndoʊˈnuːkliˌeɪs/

Technical/Scientific

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Quick answer

What does “endonuclease” mean?

An enzyme that cuts DNA at specific sites within its sequence.

Audio

Pronunciation

Definition

Meaning and Definition

An enzyme that cuts DNA at specific sites within its sequence.

Any of a class of enzymes (restriction endonucleases are a key type) that hydrolyze internal phosphodiester bonds in a DNA molecule, a fundamental tool in molecular biology and genetic engineering.

Dialectal Variation

British vs American Usage

Differences

No differences in meaning or spelling. Pronunciation differs slightly (see IPA).

Connotations

Identical scientific connotations in both varieties.

Frequency

Used with identical, extremely low, domain-specific frequency in both varieties.

Grammar

How to Use “endonuclease” in a Sentence

[endonuclease] + [verb: cleaves/cuts/digests] + [object: DNA/the plasmid]The [endonuclease] + [is/are] + [used/employed] + [to-infinitive: to cut DNA]

Vocabulary

Collocations

strong
restriction endonucleaseDNA endonucleasespecific endonucleaseendonuclease activityendonuclease digestion
medium
endonuclease enzymeendonuclease cleavagebacterial endonucleaseendonuclease site
weak
purified endonucleasecommercial endonucleasepowerful endonuclease

Examples

Examples of “endonuclease” in a Sentence

verb

British English

  • [The enzyme can endonucleolytically cleave the strand.]

American English

  • [The plasmid was endonucleased to completion.]

adverb

British English

  • [The DNA was cut endonucleolytically.]

American English

  • [The enzyme acts endonucleolytically.]

adjective

British English

  • [The endonucleolytic activity was measured.]

American English

  • [They performed an endonuclease digestion reaction.]

Usage

Meaning in Context

Business

Not used.

Academic

Central term in molecular biology research papers and textbooks.

Everyday

Virtually never used outside a scientific or educational context.

Technical

Core, precise term. Its use implies specific enzymatic function and is essential in protocols for cloning, genotyping, and sequencing.

Vocabulary

Synonyms of “endonuclease”

Strong

DNA-cutting enzyme

Neutral

restriction enzyme (a major subclass)cutter (highly informal lab slang)

Weak

nuclease (broader category)

Vocabulary

Antonyms of “endonuclease”

exonucleaseDNA ligase

Watch out

Common Mistakes When Using “endonuclease”

  • Misspelling as 'endonuclese' or 'endonuclase'.
  • Using it as a general term for any DNA-modifying enzyme.
  • Incorrect plural: 'endonucleasis' (correct: 'endonucleases').

FAQ

Frequently Asked Questions

An endonuclease cuts DNA at points *within* the polynucleotide chain, while an exonuclease removes nucleotides sequentially from the *ends* of the chain.

They cut DNA at highly specific recognition sequences, allowing scientists to reproducibly fragment DNA for analysis, cloning, and genetic engineering.

While 'endonuclease' generally refers to DNA-cutting enzymes, the term can technically apply to RNases that cut RNA internally. However, in standard usage, it is assumed to refer to DNA endonucleases unless specified otherwise.

They are produced naturally by bacteria as part of a defence system (restriction-modification system) to degrade foreign, invading DNA, such as that from bacteriophages.

An enzyme that cuts DNA at specific sites within its sequence.

Endonuclease is usually technical/scientific in register.

Endonuclease: in British English it is pronounced /ˌɛndəʊˈnjuːklɪeɪz/, and in American English it is pronounced /ˌɛndoʊˈnuːkliˌeɪs/. Tap the audio buttons above to hear it.

Phrases

Idioms & Phrases

  • [No established idioms; technical term]

Learning

Memory Aids

Mnemonic

Think: 'ENDO' means 'inside' (like 'endoscope'), and 'NUCLEASE' sounds like 'nucleus' (where DNA is). So, an enzyme that cuts DNA *inside* the strand.

Conceptual Metaphor

A molecular 'scalpel' or 'pair of scissors' that makes precise, internal cuts in the 'thread' of DNA.

Practice

Quiz

Fill in the gap
A restriction like HindIII is essential for creating recombinant DNA.
Multiple Choice

What is the primary function of an endonuclease?