DNA preparation, or DNA prep, refers to the process of isolating and purifying DNA molecules from biological samples for various downstream applications. This essential step is crucial for conducting genetic analysis, molecular biology experiments, and diagnostic assays. DNA prep techniques encompass a range of methods, including extraction, purification, quantification, and quality assessment.
2. Introduction to DNA
DNA, or deoxyribonucleic acid, is an essential
molecule found in the nucleus of living
organisms' cells. It can be compared to a
book of genetic instructions that determines
how an organism develops and functions.
3. From a chemical perspective, DNA is a
polymer of nucleotides, in other words,
a polynucleotide. A polymer is a
compound formed by many simple
units connected to each other.
4. Composition
Double helix structure:
DNA resembles a twisted ladder with two strands containing groups of four
nitrogenous bases: Adenine (A), Cytosine (C), Guanine (G), and Thymine (T).
Base pairing:
The bases are paired in the helix, specifically A pairs with T, and C pairs with G.
5. SUGAR
Nucleotides are the basic units of DNA, composed of a
phosphate group (P), a sugar (deoxyribose), and a nitrogenous
base (A, C, G, or T) that encodes genetic information.
Nucleotides
P
6. Transcription and translation
Information storage Replication
Inheritance
Basic functions of DNA
DNA stores the genetic information that
determines the characteristics and
functions of an organism.
DNA is transcribed into RNA and then
translated into proteins, which control
cellular activities.
DNA can make exact copies of
itself, which is essential for cell
division and growth.
DNA is inherited from generation to
generation and is responsible for passing
traits from parents to offspring.
8. DNA replication process
DNA replication is the process by which the DNA molecule is duplicated before a
cell divides. It begins with the separation of the two complementary DNA strands,
followed by the construction of new complementary strands from available
nucleotides. It is essential for cell reproduction and inheritance.
9. Steps of DNA replication
Strand separation:
The two DNA strands unwind and separate, breaking the hydrogen
bonds between complementary bases (A-T, C-G).
Complementation:
Free nucleotides pair with the exposed bases on each strand, following
the rules of complementarity.
Formation of new strands:
Two new DNA strands are formed, one for each original strand, using
the paired nucleotides as building blocks.
Two DNA molecules:
The result is the formation of two DNA molecules, identical to the
original, ready for cell division.
10. Importance in cell division
DNA replication is crucial during cell division (mitosis and
meiosis) as it ensures that each daughter cell receives an exact
copy of the genetic information. Without accurate replication,
genetic errors and cellular dysfunctions could occur.
11. DNA is the molecule that forms genes, and multiple genes are grouped into
chromosomes. Chromosomes are present in the nucleus of every cell and
contain all the genetic information of an organism.
DNA, genes, and chromosomes:
