Structure:
* Double helix: DNA is composed of two strands of nucleotides twisted around each other, forming a double helix.
* Nucleotides: Each strand consists of a chain of nucleotides, each containing a sugar (deoxyribose), a phosphate group, and one of four nitrogenous bases: Adenine (A), Guanine (G), Cytosine (C), and Thymine (T).
* Base pairing: The two strands are held together by hydrogen bonds between complementary bases: A pairs with T, and G pairs with C.
* Antiparallel: The two strands run in opposite directions, with one strand having a 5' phosphate group at one end and a 3' hydroxyl group at the other, while the other strand has the opposite arrangement.
Function:
* Genetic information storage: DNA carries the genetic instructions for the development, functioning, and reproduction of all living organisms.
* Replication: DNA can replicate itself, ensuring that each new cell receives a complete copy of the genetic information.
* Transcription: DNA acts as a template for the synthesis of RNA molecules, which carry genetic information to the ribosomes for protein synthesis.
Other characteristics:
* Stable molecule: DNA is a very stable molecule, capable of storing genetic information over long periods.
* Highly specific: The sequence of nucleotides in DNA determines the specific genetic information it carries.
* Located in the nucleus (in eukaryotes): DNA is primarily located in the nucleus of eukaryotic cells, where it is packaged into chromosomes.
* Circular in bacteria: In prokaryotic cells, DNA is typically circular and located in the cytoplasm.
* Can be damaged: DNA can be damaged by various factors, including radiation, chemicals, and oxidative stress.
These are just some of the key characteristics of DNA. It is a fascinating and complex molecule that plays a central role in all living organisms.
