Dictionary > Nick

Nick

Definition
noun, plural: nicks
(molecular biology) A cut or a notch in a DNA molecule due to a break in one phosphodiester bond between adjacent nucleotides of one of the two strands, often caused by an enzymatic action
(general) A small cut, dent, chip, notch, or groove
verb
To make a small cut, notch, dent, groove, or chip
Supplement
The term nick in general usage refers to a small cut, dent, chip, notch, or groove. In molecular biology, a nick is a notch or a dent in the double-stranded DNA molecule. The nick is due to the loss of one phosphodiester bond between adjacent nucleotides of one of the two strands. This is often caused by the action of a particular enzyme.
A nick forms to allow the release of torsion in the DNA strand. For instance, a plasmid that is tightly wound into a negative supercoil needs to release the torsional energy through nick formation. This causes the negative supercoil to unwind gradually until it forms into a circular shape.1
A nick may also form as a result of DNA damage. Nicking DNA may also be initiated purposely, i.e. by physical shearing, over-drying of DNA, or by administering certain enzymes (e.g. nicking endonucleases).
Ligases can repair DNA nicks by joining the 3′ hydroxyl and 5′ phosphate ends to form a phosphodiester bond.
Related term(s):

Reference(s):

1 Chao, J., Zhang, L., and Wang, P. (2015). “Configuration Transitions of Free Circular DNA System Induced by Nicks”. Journal of Nanomaterials. doi:10.1155/2015/546851


You will also like...

bryophyte - sporophyte and gametophyte
Meiosis and Alternation of Generations

Plants are characterized by having alternation of generations in their life cycles. This tutorial is a review of plant m..

IQ, Creativity and Learning
IQ, Creativity and Learning

Human intelligence provided the means to utilize abstract ideas and implement reasoning. This tutorial takes a further l..

Human gastrointestinal tract
Human Biology – Food and Digestion

This tutorial recognizes the importance of food as a source of energy that will fuel many biological processes. A good d..

Cell Respiration
Cell Respiration

Cell respiration is the process of creating ATP. It is "respiration" because it utilizes oxygen. Know the different stag..

Water Cycle
The Water Cycle

The water cycle (also referred to as the hydrological cycle) is a system of continuous transfer of water from the air, s..

Digestion and Absorption of Food
Digestion and Absorption of Food

The gastrointestinal system breaks down particles of ingested food into molecular forms by enzymes through digestion and..