Where are the instructions for life located?

The nucleus of every human cell carries a set of unique codes for making new cells to build and maintain the body. These instructions are called genes, and they are made of a substance called DNA.

Inside the cell nucleus, there are 46 tiny structures called chromosomes. These are made of tightly coiled strands of DNA, which contain all the information the cell needs to make a new, identical version of itself. Every time a cell divides so the body can grow or repair itself, a DNA strand “unzips” down the middle. Each unzipped half then rebuilds itself into a new DNA strand, identical to the original and carrying all the same codes.

The DNA molecule

Magnified, a strand of DNA looks like a twisted ladder, with two long, thin strands connected by rungs. These rungs are called bases, and are made up of four different chemicals. The bases, and are made up of four different chemicals. The bases interact to form instructions for making proteins – the building materials that make up our organs, muscles, blood, bones and hair.

Chromosome

Inside a cell nucleus there are 46 chromosomes (23 pairs), made of tightly packed DNA.

Histone

This ball-shaped protein acts as a framework for DNA to coil around.

Double helix

The twisted ladder shape of a DNA molecule is known as a double helix.

Backbone

The two long, thin parts of the DNA strand are known together as the backbone.

Pairing up

DNA bases are made up of your chemicals – adenine, cytosine, guanine, and thymine. The bases link together in pairs. The specific order of the base pairs along the ladder gives the instructions for making different proteins.

The order of the base pairs creates different codes to form different proteins. Adenine always links to thymine. Guanine always joins with cytosine.

 

Picture Credit : Google