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What errors during DNA replication are minimized and how?
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DNA Polymerase has proofreading capabilities to minimize errors, ensuring an error rate of about 1 in 10 billion nucleotides.
Who were awarded the Nobel Prize for the discovery of DNA’s structure and who was notably excluded?
James Watson and Francis Crick were awarded the Nobel Prize, while Rosalind Franklin was not, due to posthumous disqualification.
What was Friedrich Miescher's contribution to the discovery of DNA?
Friedrich Miescher discovered DNA in 1869, laying the foundation for future discoveries about its structure and function.
What is the significance of the 5' to 3' and 3' to 5' directionality in the DNA structure?
The 5' to 3' and 3' to 5' directionality refers to the opposite chemical directions of the two DNA strands, which is important for the replication and transcription processes.
What significant discovery was made using X-ray diffraction and by whom?
Rosalind Franklin used X-ray diffraction to confirm the helical structure of DNA.
Define the term ‘genetic code’ as it pertains to DNA.
The genetic code in DNA consists of sequences of nucleotides that encode instructions for synthesizing proteins, determining cellular activities and characteristics of an organism.
Describe the base pairing rules in DNA.
In DNA, Adenine (A) pairs with Thymine (T), and Guanine (G) pairs with Cytosine (C). These pairs are bonded by hydrogen bonds.
Describe the structure and function of the double helix in DNA.
DNA's double helix structure consists of two molecules bonded together, resembling a twisted ladder with sugar-phosphate backbones and base pairs read through complementary bonding.
How does a nucleotide in DNA differ from a nucleotide in RNA?
A DNA nucleotide contains a deoxyribose sugar and the base thymine (T), whereas an RNA nucleotide contains a ribose sugar and the base uracil (U) instead of thymine.
What is the function of ligase in DNA replication?
Ligase joins the Okazaki fragments on the lagging strand to create a continuous DNA strand.
How do the roles of mRNA, tRNA, and rRNA differ in protein synthesis?
mRNA carries genetic information from DNA to ribosomes, tRNA transfers specific amino acids to the ribosome, and rRNA forms the catalytic part of the ribosome and is essential for protein synthesis.
What roles do DNA Helicase and DNA Polymerase play in DNA replication?
DNA Helicase unwinds the DNA helix, while DNA Polymerase adds nucleotides to the growing DNA strand and has proofreading capabilities to ensure minimal errors.
Compare the sugar components of DNA and RNA.
DNA contains deoxyribose, a five-carbon sugar lacking one oxygen atom compared to ribose, the sugar found in RNA.
What structural difference accounts for the single-stranded nature of RNA compared to DNA?
RNA is single-stranded because it uses the sugar ribose, which includes an extra oxygen atom compared to deoxyribose in DNA, providing a different structure that is less stable for double-helix formation.
Explain the roles of the leading and lagging strands during DNA replication.
The leading strand is synthesized continuously in the 5' to 3' direction, whereas the lagging strand is synthesized in short segments called Okazaki fragments.
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