DNA Basics
What does DNA stand for?
Deoxyribonucleic acid
What is the name of the pentose sugar in RNA?
Ribose
What is a polynucleotide strand?
A chain of nucleotides linked together
What forms the backbone of DNA?
Alternating deoxyribose sugars and phosphate groups
What is a codon?
A triplet of bases that codes for an amino acid
Where is most DNA located in eukaryotic cells?
In the nucleus
Which base does RNA have instead of thymine?
Uracil
Purines and pyrimidines
What does "antiparallel" mean in the context of DNA strands?
One strand runs 5' to 3', and the other runs 3' to 5'
Why is the genetic code considered universal?
It is the same across almost all living organisms
What are the components of a nucleotide in DNA?
A pentose sugar, a phosphate group, and a nitrogenous base
What is the function of mRNA?
Carries genetic information from DNA to the ribosome for protein synthesis
Which nitrogenous bases are purines?
Adenine (A) and Guanine (G)
What is the significance of the antiparallel arrangement of DNA strands?
It allows enzymes like DNA polymerase to read and replicate the strands properly during DNA replication
What is the role of the coding strand in DNA?
Contains the sequence that is transcribed into RNA
What is the term for DNA's double-stranded structure?
Double helix
Where is RNA found in eukaryotic cells
Mostly in the cytoplasm (some may be found in the nucleus where it is synthesized.)
Which nitrogenous bases are pyrimidines?
Cytosine (C), Thymine (T), and Uracil (U)
What is the role of complementary base pairing in DNA replication?
It ensures that each new DNA strand is an exact copy of the original by matching the correct bases during replication.
What is the significance of the universal genetic code?
Enables genetic engineering and indicates a common ancestry for all life
What type of bonds link the two strands of DNA together?
Hydrogen bonds
How does the structure of RNA differ from DNA?
RNA is single-stranded, contains ribose instead of deoxyribose, and replaces thymine with uracil.
Name the purine and pyrimidine bases that pair in DNA, and specify the type and number of bonds that hold each pair together.
Adenine (purine) pairs with Thymine (pyrimidine) via two hydrogen bonds, and Guanine (purine) pairs with Cytosine (pyrimidine) via three hydrogen bonds.
What role do hydrogen bonds play in the stability of the DNA double helix?
Hydrogen bonds between complementary base pairs stabilize the DNA structure while still allowing the strands to separate for replication or transcription.
How does the sequence of bases in DNA determine the traits of an organism?
The sequence of bases encodes the instructions for synthesizing proteins, which determine the structure and function of cells, influencing traits.