DNA Properties

NewsGuard 100/100 Score

DNA or deoxyribonucleic acid is the basic hereditary material present in all the cells of an organism and basically provides a blue print for the cell’s functions, growth, reproduction and death. The structure of the DNA called the double-stranded helical structure was first described by Watson and Crick in 1953.

From then enormous progress has been made in synthesis, sequencing, and manipulation of DNA. The DNA these days can be sequenced or analysed for minute details and even genes may be inserted to cause changes in the DNA function and structure.

This illustration depicts DNA packed tightly into chromosomes, as well as a DNA molecule unwound to reveal its 3-D structure. Credit: Darryl Leja, NHGRI
This illustration depicts DNA packed tightly into chromosomes, as well as a DNA molecule unwound to reveal its 3-D structure. Credit: Darryl Leja, NHGRI

Structure of DNA

The DNA is a polymer molecule with four types of basic chemicals. These are called the deoxyribonucleotides. They contain:

  • a sugar (deoxyribose)
  • a negatively charged phosphate group
  • the bases:
    • adenine (A)
    • cytosine (C)
    • guanine (G)
    • thymine (T)

The nucleotides are linked together by covalent phosphodiester bonds.

Double stranded helix

When looking at the structure, Watson and Crick found that DNA is a double stranded helix or a ladder that is twisted. Here the bases form the rungs of the ladder and the sugar phosphates are on the outside.

There are hydrogen bonds between a large purine base (A or G) on one strand and a small pyrimidine base (T or C) on the other chain. The base-pair sequence is usually referred to as the primary structure of DNA. This sequence determines the actual structure of the DNA.

Why is DNA important?

DNA carries the genetic code and this is what is read by the protein synthesis mechanism when it makes new proteins.

The relationship between DNA and proteins is vital for living organisms. A protein is an abundant and complex molecule found in the body. These may be important for forming the body structure (Structural proteins), messengers, enzymes, hormones etc.

Shape and handedness of DNA

DNA can have a variety of shapes and lengths. Under physiological conditions DNA is found in the so-called B-form, a right-handed double-stranded helix. There is a repeat twist or helix after every 10.4 base pairs or around 34nanometers. The thickness of the DNA is about 2nm and a base pair thickness is about 0.34nm.

DNA Grooves

As the DNA strands are twisted they have distinct grooves. DNA has two kinds of grooves that play important roles in its functioning. Major and minor grooves help in formation of different proteins. These grooves bind proteins like transcription factors that lead to formation of the proteins.

Conformations of DNA

DNA can be present in several different conformations and these are important for DNA functions and actions. Conformations of DNA are vital for the repair of damaged DNA because they act with the enzymes in the body.

DNA Supercoiling

The DNA strands are like a phone cable or a rope. This coiling is a central property of DNA. DNA can be in a relaxed or a coiled state. Coiling helps the extremely long DNA strands to fit into the tiny cell nucleus. Put simply, this supercoiling property makes DNA more efficient packing in more information in small spaces.

What is DNA Sense and Antisense?

RNA or ribonucleic acid is a cousin of DNA. DNA actually codes for RNA and holds the codes for the amino acids that are building blocks for proteins.

The antisense strand is the DNA strand that carries important information to make proteins. This antisense strand is the key for making proteins. The sense strand is the other strand that does not code for RNA.


  1. https://www2.mpip-mainz.mpg.de/
  2. http://www.exploredna.co.uk/learn-about-dna-structure.html
  3. http://mbb.rutgers.edu/315-NP/315-Ch1Basics.pdf
  4. https://www.cliffsnotes.com/
  5. http://biology.kenyon.edu/courses/biol63/watson_06.pdf
  6. https://cmgm-new.stanford.edu/

Further Reading

Article Revisions

  • Feb 8 2024 - Main body of text edited to improve clarity and scientific accuracy.

Last Updated: Feb 8, 2024

Dr. Ananya Mandal

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Mandal, Ananya. (2024, February 08). DNA Properties. News-Medical. Retrieved on June 14, 2024 from https://www.news-medical.net/life-sciences/DNA-Properties.aspx.

  • MLA

    Mandal, Ananya. "DNA Properties". News-Medical. 14 June 2024. <https://www.news-medical.net/life-sciences/DNA-Properties.aspx>.

  • Chicago

    Mandal, Ananya. "DNA Properties". News-Medical. https://www.news-medical.net/life-sciences/DNA-Properties.aspx. (accessed June 14, 2024).

  • Harvard

    Mandal, Ananya. 2024. DNA Properties. News-Medical, viewed 14 June 2024, https://www.news-medical.net/life-sciences/DNA-Properties.aspx.


The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.

You might also like...
Ancient viral sequences in the human genome may contribute to psychiatric disorder susceptibility