DNA replication is the process by which a cell makes an identical copy of its DNA. It's a crucial step in cell division, ensuring that each daughter cell receives an accurate and complete set of genetic information. Here's an overview of the key steps involved in DNA replication:
1. **Initiation**: The process begins at specific sites on the DNA molecule called origins of replication. Proteins bind to these origins and separate the DNA strands, forming a replication bubble.
2. **Unwinding**: Enzymes called helicases unwind the double helix structure of the DNA molecule, breaking the hydrogen bonds between the complementary base pairs.
3. **Priming**: Primase, a specialized enzyme, synthesizes a short RNA primer complementary to the DNA template strand. This primer provides a starting point for DNA synthesis.
4. **Elongation**: DNA polymerase enzymes add nucleotides to the growing DNA strand, using the complementary base-pairing rule (A pairs with T, and G pairs with C). DNA polymerase can only add nucleotides in the 5' to 3' direction, so replication occurs in a continuous manner on one strand (leading strand) and discontinuously in short fragments on the other strand (lagging strand).
5. **Proofreading and Correction**: DNA polymerase has a proofreading function that checks each nucleotide as it's added to ensure accuracy. If an incorrect nucleotide is added, the enzyme excises the incorrect nucleotide and replaces it with the correct one.
6. **Termination**: DNA replication continues until it reaches the end of the DNA molecule or encounters another replication fork from an adjacent origin of replication. Specialized proteins help stabilize the newly synthesized DNA strands and remove the RNA primers, which are later replaced with DNA nucleotides by DNA polymerase.
The result of DNA replication is two identical double-stranded DNA molecules, each containing one original (parental) strand and one newly synthesized (daughter) strand. These replicated DNA molecules can then be distributed into daughter cells during cell division, ensuring genetic continuity and inheritance of traits
Chris Khan Academy
DNA replication is the process by which a cell makes an identical copy of its DNA. It's a crucial step in cell division, ensuring that each daughter cell receives an accurate and complete set of genetic information. Here's an overview of the key steps involved in DNA replication:
1. **Initiation**: The process begins at specific sites on the DNA molecule called origins of replication. Proteins bind to these origins and separate the DNA strands, forming a replication bubble.
2. **Unwinding**: Enzymes called helicases unwind the double helix structure of the DNA molecule, breaking the hydrogen bonds between the complementary base pairs.
3. **Priming**: Primase, a specialized enzyme, synthesizes a short RNA primer complementary to the DNA template strand. This primer provides a starting point for DNA synthesis.
4. **Elongation**: DNA polymerase enzymes add nucleotides to the growing DNA strand, using the complementary base-pairing rule (A pairs with T, and G pairs with C). DNA polymerase can only add nucleotides in the 5' to 3' direction, so replication occurs in a continuous manner on one strand (leading strand) and discontinuously in short fragments on the other strand (lagging strand).
5. **Proofreading and Correction**: DNA polymerase has a proofreading function that checks each nucleotide as it's added to ensure accuracy. If an incorrect nucleotide is added, the enzyme excises the incorrect nucleotide and replaces it with the correct one.
6. **Termination**: DNA replication continues until it reaches the end of the DNA molecule or encounters another replication fork from an adjacent origin of replication. Specialized proteins help stabilize the newly synthesized DNA strands and remove the RNA primers, which are later replaced with DNA nucleotides by DNA polymerase.
The result of DNA replication is two identical double-stranded DNA molecules, each containing one original (parental) strand and one newly synthesized (daughter) strand. These replicated DNA molecules can then be distributed into daughter cells during cell division, ensuring genetic continuity and inheritance of traits
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