DNA, or Deoxyribonucleic Acid, is the
fundamental molecule of life. It serves as
the blueprint that contains all the genetic
information needed to build and maintain
living organisms. DNA is found in the
nucleus of every cell in our bodies.
DNA has a unique double helix structure,
first discovered by Watson and Crick.
It consists of two complementary strands
twisted around each other like a spiral
staircase. Each strand contains nucleotides
with four different bases.
DNA performs three crucial functions
in living organisms. First, it stores
all genetic information that determines
our traits. Second, it replicates itself
during cell division to pass on genetic
information. Third, it guides the
synthesis of proteins.
DNA is fundamental to life as we know it.
It determines all inherited traits, enables
reproduction and evolution, and allows
organisms to function properly. Understanding
DNA has revolutionized medicine and
biotechnology, leading to breakthroughs
in gene therapy and genetic engineering.
DNA is composed of four nucleotide bases:
Adenine, Thymine, Guanine, and Cytosine.
These bases have specific pairing rules:
Adenine always pairs with Thymine,
and Guanine always pairs with Cytosine.
The sugar-phosphate backbone forms
the structural framework of DNA,
holding the bases together in a
stable double-stranded molecule.
The DNA double helix forms when two
complementary strands twist around
each other in a right-handed spiral.
The two strands are antiparallel,
meaning they run in opposite directions.
Base pairs connect the strands in the center,
while the sugar-phosphate backbones
form the outer structure. This twisted
ladder-like structure provides both
stability and flexibility to the DNA molecule.
DNA performs three essential functions
in living organisms. First, it stores
genetic information that determines
traits like eye color, height, and
blood type. Second, DNA enables
heredity by passing genetic information
from parents to offspring, maintaining
species characteristics across generations.
Third, DNA provides instructions for
protein synthesis, coding for enzymes,
hormones, and antibodies that control
cellular functions and biological processes.
DNA replication is a precise process
that creates identical copies of DNA.
First, the double helix unwinds and
the two strands separate at the
replication fork. Each original strand
serves as a template for building
a new complementary strand.
DNA polymerase enzyme adds nucleotides
to form the new strands. This process
is called semiconservative because
each new DNA molecule contains
one original strand and one newly
synthesized strand, ensuring accurate
transmission of genetic information.