DNA, or deoxyribonucleic acid, is the hereditary material in humans and most organisms, forming a double helix structure with nucleotides. These nucleotides include adenine, cytosine, guanine, and thymine, which pair specifically to ensure accurate genetic replication and transcription. DNA replication is a high-fidelity process involving enzymes like DNA polymerases, with proofreading mechanisms to maintain genetic integrity. Mutation rates, although low, contribute to evolution and adaptation.
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Nucleotides are the building blocks of DNA, consisting of a sugar molecule, a phosphate group, and one of four nitrogenous bases
Purines
Adenine and guanine are purines, larger two-ring structures that pair with pyrimidines in DNA
Pyrimidines
Cytosine and thymine are pyrimidines, smaller one-ring structures that pair with purines in DNA
DNA is composed of two long strands that form a double helix, with complementary base pairing between the nitrogenous bases stabilizing the structure
DNA replication is the biological process of producing two identical copies of DNA from one original molecule
DNA Polymerases
DNA polymerases are enzymes that add nucleotides to the growing DNA strand during replication
Primer
A primer is required to initiate DNA synthesis by providing a starting point for DNA polymerases
DNA replication has a high fidelity due to proofreading mechanisms, but mutations can occur at a low frequency, contributing to genetic variation and evolution
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DNA's fundamental role
Encodes genetic instructions for development and functioning of organisms.
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DNA double helix structure
Two long strands form a twisted ladder, providing stable yet flexible genetic storage.
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Purines vs Pyrimidines
Adenine and guanine are larger purines with two rings; cytosine and thymine are smaller pyrimidines with one ring.
