What is DNA and How Does It Work? Structure & Function

What is a DNA Molecule?

DNA is a type of molecule that contains the genetic instructions used in the development and functioning of all known living organisms. DNA molecules allow this information to be passed from one generation to the next.

What is DNA Made of? (Structure of DNA)

On April 25th, 1953, Watson and Crick introduced the model of DNA. According to that model, DNA is a double helix that contains two complementary strands.

Each strand has a backbone made of sugar phosphate. One strand is in the 5′ to 3′ direction with respect to carbon atoms on the sugar, and the complementary strand is in the 3′ to 5′.

Deoxyribonucleic acid (DNA) consists of two long polymers of simple units called nucleotides. DNA is a polymer built from the monomer deoxyribonucleic acid.

Nucleotides and Bases

Four types of nucleotides make up DNA, and there are 3 parts to each deoxyribonucleic acid.


They are;

  • Deoxyribose sugar,
  • Phosphate group,
  • Nitrogenous base.

These two long strands form a double helix, each serving as a template for a single strand of the other.

The nucleotide bases are;

  • adenine,
  • thymine,
  • cytosine,
  • guanine.

The two strands are chemically attracted to each other in a way that allows them to be joined together easily, according to base-pairing rules: A is paired with T, and C is paired with G. The resulting molecule is called DNA.

Macro Structure of DNA

The distance between each base pair is 0.34 nm, the distance of one turn is 3.4 nm, and the distance between the two strands is 2.37 nm. A DNA molecule contains a major grove and a minor grove.

The unique structure of the chromosome keeps DNA tightly wrapped around spool-like proteins called histones. Without such a packing, DNA molecules would be too long to fit inside cells.

Chromosomes are a key part of the process that ensures DNA is accurately copied and distributed in the vast majority of cell divisions.

Each chromosome contains all the information needed to give you a base for your physical and emotional characteristics.

DNA Structure

There are 3 types of DNA;

  • B DNA – right-handed helix,
  • A DNA -Left-handed helix,
  • Z DNA -right-handed helix.

DNA is a molecule that contains genetic information. It is the blueprint of a living organism. DNA has four different functions:

  • It stores genetic information,
  • It replicates,
  • It repairs DNA, and
  • It regulates cell division and growth.


What do you think?

Written by Rylan Santos

Full-Stack Web Developer, Digital Marketing, and E-Business Builder.

Leave a Reply

Your email address will not be published. Required fields are marked *

GIPHY App Key not set. Please check settings

healthy meal for weight loss

The Secret to Successful Weight Loss with Healthy Meals

Top List Beautiful Places to Travel without a Passport (Open list) (10 submissions)