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...

Homeostasis by water regulation
Homeostasis of Organism Water Regulation

Osmoregulation is the regulation of water concentrations in the bloodstream, effectively controlling the amount of water..

Pink Lotus plant on a pond
Freshwater Lentic Communities & Animals

This tutorial looks at some of the communities in freshwater lentic habitats. For instance, symbiosis occurs in a commun..

Selective Breeding
Selective Breeding

Gregor Mendel's studies into Monohybrid and Dihybrid crossing and Charles Darwin's study of evolution and natural select..

Developmental Biology
Developmental Biology

Developmental biology is a biological science that is primarily concerned with how a living thing grows and attains matu..

Consciousness and behavior
Consciousness and Behavior

Human consciousness and behavior are an interesting topic since they are determined and controlled by the brain. Conscio..

Regulation of Biological Systems
Regulation of Biological Systems

Regulation of Biological Systems tutorials are focused on the modulation of biological systems from cell to population l..