DNA : A carrier of genetic information

Deoxyribonucleic acid

DNA as a genetic material

  • First extracted from, nuclei in 1870
  • Named “nuclein”
  • Chemical analysis: determined DNA as a weal acid and rich in Phosphorous
  • Furthered named DNA, as lot of information provided by name:

Deoxyribonucleic acid                       

Contains sugar (deoxyribose)

Weakly acidic

Found in Nucleus

  • Only four different subunits makes up DNA
  • Chromosome contains less DNA than protein by weight
  • Chemical structure of DNA:
  • Located in the nucleus of a cell like a coiled noodle.
  • Main purpose is to code genetic information.
  • During Replication, it attains a structure called Chromosomes.
  • DNA basically is a polymer.
  • Polymer is a molecule consisting of many repeating units, which are called Monomers.
  • i.e., Polymer = (monomer, monomer, monomer, monomer, monomer, monomer, monomer , monomer, monomer)
Mb Polymers - Lessons - Tes Teach

ex. Starch = (glucose, glucose, glucose, glucose, glucose, glucose)

that means,

DNA = (Nucleotides)

  1. Nucleotides: these are biopolymers, a DNA molecule look like a rope ladder which is made up of units: nucleotides
How do you draw a nucleotide and label its three basic parts? | Socratic
  1. Basic structure of a Nucleotide contains:

A phosphate group

Deoxyribose(5C) sugar

Nitrogenous base : Purines and Pyrimidines i.e., Adenine, Guanine, Cytosine, Thymine.

Purines vs Pyrimidines - Difference and Comparison | Diffen

Q. how two nucleotides are joined together?

A. By Sugar-Phosphate backbone.

  • Base pairing

Adenine and Thymine (double bond)

Cytosine and Guanine (triple bond)

By H-bonding

  • The order of these bases is what determines DNA’s instructions, or genetic code.
  • Human DNA has around 3 billion bases and more than 99% of those bases are the same in all people.
  • Nucleotides are attached together to form 2 long strands that spiral to create a structure – Double helix. Its like a ladder.
  • Nucleosides: N-bases + sugars
  • Nucleotides: N-bases + sugars + phosphate group

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