In order for a cell to divide, it must first make a
copy
of its own DNA, which is the genetic code it needs to function properly. It is very important that your DNA is replicated accurately, with new cells receiving an exact copy of your genetic sequence.
Why is it so important that DNA replicates correctly every time?
DNA replication needs to occur
because existing cells divide to produce new cells
. Each cell needs a full instruction manual to operate properly. So the DNA needs to be copied before cell division so that each new cell receives a full set of instructions!
Why is it important for DNA replication to occur without any mistakes?
When replication mistakes are not corrected,
they may result in mutations
, which sometimes can have serious consequences. Point mutations, one base substituted for another, can be silent (no effect) or may have effects ranging from mild to severe.
Why DNA can copy itself exactly?
DNA Replication How DNA Makes Copies of Itself. Before a cell divides, its DNA is replicated (duplicated.) Because
the two strands of a DNA molecule have complementary base pairs, the nucleotide sequence of each strand automatically supplies the information needed to produce its partner
.
What actually happens to DNA before it can be replicated copied?
Before replication can occur, the length of the DNA double helix about to be copied must be unwound. … The
enzyme DNA polymerase then moves along the exposed DNA strand
, joining newly arrived nucleotides into a new DNA strand that is complementary to the template.
What will happen if there is a mistake in DNA replication?
When Replication Errors
Become Mutations
.
Incorrectly paired nucleotides that still remain following mismatch repair become permanent mutations after the next cell division
. This is because once such mistakes are established, the cell no longer recognizes them as errors.
What happens if DNA replication does not occur?
The DNA replication occurs at the synthesis phase of the cell cycle. The cell cycle is regulated at each stage. If DNA replication does not occur, then
the cell cycle will not proceed to the next stage and the subsequent division will not happen
. It will lead to cell death.
Where does DNA replication happen?
DNA replication occurs
in the cytoplasm of prokaryotes and in the nucleus of eukaryotes
. Regardless of where DNA replication occurs, the basic process is the same. The structure of DNA lends itself easily to DNA replication.
In which phase does DNA copy itself?
In the eukaryotic cell cycle, chromosome duplication occurs during
“S phase”
(the phase of DNA synthesis) and chromosome segregation occurs during “M phase” (the mitosis phase).
What are the 5 steps in DNA replication?
- Step 1: Replication Fork Formation. Before DNA can be replicated, the double stranded molecule must be “unzipped” into two single strands.
- Step 2: Primer Binding. The leading strand is the simplest to replicate.
- Step 3: Elongation.
- Step 4: Termination.
What makes DNA so stable?
The main bonding in DNA which renders the double helix structure so stable is that
of hydrogen bonds
. Between the complementary base pairs, hydrogen bonds connect the two strands of the helix. There are 3 H bonds between Guanine and Cytosine and 2 between Adenine and Thymine.
What are the three major steps in DNA replication?
Replication occurs in three major steps:
the opening of the double helix and separation of the DNA strands, the priming of the template strand, and the assembly of the new DNA segment
.
What are the 4 steps of replication?
- Step 1: Replication Fork Formation. Before DNA can be replicated, the double stranded molecule must be “unzipped” into two single strands.
- Step 2: Primer Binding. The leading strand is the simplest to replicate.
- Step 3: Elongation.
- Step 4: Termination.
What are the major key players in DNA replication?
One of the key players is
the enzyme DNA polymerase
, also known as DNA pol. In bacteria, three main types of DNA polymerases are known: DNA pol I, DNA pol II, and DNA pol III. It is now known that DNA pol III is the enzyme required for DNA synthesis; DNA pol I and DNA pol II are primarily required for repair.
What foods help repair DNA?
One food shown to repair DNA is
carrots
. They are rich in carotenoids, which are powerhouses of antioxidant activity. A study that had participants eating 2.5 cups of carrots per day for three weeks found, at the end, the subjects’ blood showed an increase in DNA repair activity.
How does DNA polymerase fix mistakes?
Most of the mistakes during DNA replication are promptly corrected by DNA polymerase
by proofreading the base that has just been added
(Figure 1). In proofreading, the DNA pol reads the newly added base before adding the next one, so a correction can be made.
