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DNA functions. DNA is the only molecule that can make copies of itself. This process is crucial in making sure that all newly formed cells get a full set of genetic blue prints during cell division.
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DNA is the only molecule that can make copies of itself. This process is crucial in making sure that all newly formed cells get a full set of genetic blue prints during cell division
Another key function of DNA is to act as the blue prints that are used by cells to make sure that all the structural and functional proteins are properly built in the body.
The last function of DNA is that it may undergo random mutations, that may ocassionally give rise to new genes that that may produce new improved proteins.
At this time our focus will be on how DNA can copy itself. This process is known as REPLICATION. This must take place prior to cell division.
Fig. 25.2 Recall that DNA consists of two strands that perfectly compliment each other.
The first step in Replication is the unwinding and unzipping of the Double Helix. This first process is driven by an enzyme called “HELICASE” Helicase
Replication of DNA takes place inside the nucleus of the cell. Floating around in the nucleoplasm (fluid) are millions of free-floating DNA Nucleotides. These nucleotides are drawn toward the two open strands, their bases than latch on to the open bases to form H-Bonds.
A number of enzymes called “DNA Polymerases” are responsible for the following: • Double checking to make sure that the correct bases properly base pair. • Run dehydration synthesis between the new incoming DNA Nucleotides to form a complete strand. • Trigger each double stranded DNA to take on its double helix shape.
Fig. 25.3 DNA Polymerases in action
Replication is often referred to as “Semi-Conservative” Replication, because in each new double stranded DNA, there exists a single strand of the original DNA conserved.
