Comprehensive Report on DNA Replication: Process and Significance

This report provides an overview of DNA replication, a fundamental process for biological inheritance. It highlights that DNA is a double helical structure made of nucleotides, each containing a nitrogen base, sugar, and phosphate group. The four nitrogenous bases are adenine, thymine, guanine, and cytosine. DNA replication produces two identical copies of DNA from a single original strand and is essential for cell division. The mechanism is similar across organisms and includes semi-conservative, conservative, and disruptive forms. Key aspects of DNA replication include its semi-conservative nature, initiation at the origin, synthesis in the 5’-3’ direction, semi-discontinuous replication, the need for RNA primers, and the formation of Okazaki fragments on the lagging strand. The lagging strand experiences a slight delay and undergoes discontinuous replication in small fragments.

DNA Replication

INTRODUCTION
• DNA is a double helical structure and are made
up of Nucleotides.
• Each nucleotides are made up of a nitrogen base,
a sugar group, phosphate group.
• The 4 types of nitrogenous bases are: Adenine
(A), Thymine (T), Guanine (G), Cytosine (C)
(Sinden 2012).

INTRODUCTION
DNA replication also deals with production of two identical copies of
DNA from a single original DNA stand or molecule. This DNA
replication is the basis of biological inheritance across all forms of
organisms. The cell possesses the capability to divide, thus making
DNA replication a vital part. Approximately, around 6.5 billion base
pairs of DNA exists within the genome. The mechanism of DNA
replication is similar across all the organisms (Bochman and
Schwacha 2015). The three different forms of DNA replication are:
Semi-conservative, Conservative and Disruptive.

IMPORTANT POINTS TO NOTE ON DNA REPLICATION
• DNA replication is semi-conservative in nature
• Starts at the origin
• The process of synthesis always initiates at the 5’-3’ direction
• The nature of replication is semi-discontinuous
• RNA primers are required
• Okazaki fragments are the short forms of the newly formed
DNA fragments on the lagging template.
• Lagging strand is one of the two strands that are found in the
replication fork. The lagging strand requires a slight delay in
replication, this strand undergoes replication discontinuously
in small fragments (Bryant and Aves 2011).

START OF DNA REPLICATION

DNA REPLICATION continued…

REFERENCE
Bochman, M.L. and Schwacha, A., 2015. DNA replication: strand separation unravelled. Nature, 524(7564),
p.166.
Bryant, J.A. and Aves, S.J., 2011. Initiation of DNA replication: functional and evolutionary aspects. Annals of
botany, 107(7), pp.1119-1126.
Blitzblau, H.G., Chan, C.S., Hochwagen, A. and Bell, S.P., 2012. Separation of DNA replication from the assembly
of break-competent meiotic chromosomes. PLoS genetics, 8(5), p.e1002643.
Clark, D.P. and Pazdernik, N.J., 2009. DNA-Synthese in vivo und in vitro. In Molekulare Biotechnologie (pp. 87-
117). Spektrum Akademischer Verlag.
Sinden, R.R., 2012. DNA structure and function. Elsevier.