Dictionary » M » Molecule



noun, plural: molecules

A tiny or a very small piece (of something).

(biology or biochemistry) An extremely small particle or substance, especially at cellular or structural level, as a biomolecule.

(physics and chemistry) The smallest unit of an element or compound, made up of two or more atoms held together by strong chemical bond.


In physics and chemistry, a molecule is an electrically neutral, group of atoms that can exist alone in free state while its characteristic properties are retained. The atoms comprising the molecule may be of the same kind (as in oxygen molecule made up of two oxygen atoms) or of different kinds (such as water molecule made up of oxygen and hydrogen).

In biology, particularly in biochemistry, a molecule is used less strictly that it can also refer to any minute particle such as charged organic molecules or to substances (called biomolecules) produced and occur naturally in living organisms such as proteins, carbohydrates, DNA, etc.

Word origin: French molécule, from New Latin mōlēcula, diminutive of Latin mōlēs, mass.
Related forms: molecular (adjective)

Related terms:

Please contribute to this project, if you have more information about this term feel free to edit this page

Results from our forum

Xenobiotic Agents for Biofilm Prevention and Treatment

... Biofilms are a serious problem in the clinic due to three key factors: (1) the extracellular matrix limits diffusion of molecules such as antibiotics, preventing them from readily accessing the target bacteria; (2) some bacteria within the biofilm are dormant, which diminishes ...

See entire post
by bioCassie
Tue Mar 03, 2015 5:38 pm
Forum: Microbiology
Topic: Xenobiotic Agents for Biofilm Prevention and Treatment
Replies: 0
Views: 289

Re: immunoglobulins

... cells and found in the serum and in other body fluids and tissues, including the urine, spinal fluid, lymph nodes, and spleen. Each immunoglobulin molecule consists of four polypeptide chains: two heavy chains (H chains) and two light chains (L chains). There are five antigenically different kinds ...

See entire post
by RZachary1
Wed Jan 14, 2015 5:49 am
Forum: Cell Biology
Topic: immunoglobulins
Replies: 2
Views: 2291

I have got some BIG issues! forgive the long post

... : I know yo target the genes that are in severe proximity to our targeted gene and that you make use a fluorescent nucleotide or a tagged reporter molecule that will attach themselves to those genes and fluorescent in order to show presence of the bad genes :p. but a bit more knowledge might be ...

See entire post
by saddy51
Sun Jan 04, 2015 10:39 am
Forum: Genetics
Topic: I have got some BIG issues! forgive the long post
Replies: 1
Views: 1906


usually 1 nm and higher. Size of atoms (C, N) is 70 pm and smaller. That's 20-times less. However, you may be interested in the new one-molecule sequencing methods. And separation of chromosomes by dissection by laser is also nothing new.

See entire post
by alden
Fri Oct 10, 2014 6:34 am
Forum: Microbiology
Topic: ID OF UNKNOWN?!?!
Replies: 6
Views: 6248

Re: Chromatin

Before replication there were 23 pairs of molecules, 23 of maternal origin and 23 of paternal origin, plus the maternally-contributed mitochondrial chromosome (which I'll ignore for the rest of this post). Counting chromosomal centromeres, there ...

See entire post
by jonmoulton
Thu Sep 04, 2014 3:04 pm
Forum: Genetics
Topic: Chromatin
Replies: 2
Views: 4270
View all matching forum results

This page was last modified 09:54, 19 February 2009. This page has been accessed 95,488 times. 
What links here | Related changes | Permanent link