Structure of DNA

• What are the three main components of DNA?

  Deoxyribose, Phosphate, Nitrogenous bases
• What are the four types of nitrogenous bases in DNA?

  Adenine, Guanine, Cytosine, Thymine
• How does phosphate contribute to the structure of DNA?

  It attaches to deoxyribose to create the backbone
• What is the structure of DNA and its components?

  • Deoxyribose: Sugar molecule in the backbone
  • Phosphate: Connects deoxyribose, forming the backbone
  • Nitrogenous bases:
  • Adenine (A)
  • Guanine (G)
  • Cytosine (C)
  • Thymine (T)
  • Nitrogenous bases store and carry genetic information
• What are the four DNA bases?

  Adenine, Thymine, Cytosine, Guanine
• What is the purpose of the sugar-phosphate backbone in the DNA molecule?

  It provides structural support and allows the DNA molecule to form a double helix
• What is the name of the sugar component in a DNA nucleotide?

  Deoxyribose
• What are the components of a nucleotide?

  • Phosphate
  • Sugar (deoxyribose)
  • Base (A, T, C or G)
• What are the four DNA bases that form the base pairs in the double helix?

  • Adenine (A)
  • Thymine (T)
  • Cytosine (C)
  • Guanine (G)
• What is the role of the sugar-phosphate backbone in the DNA double helix?

  • Provides structural support and stability to the double helix
  • Connects the nucleotides together
• How do DNA strands achieve stability?

  • Strands pair up through nitrogenous bases
  • Base pairing creates hydrogen bonds
• What are the components of the DNA double helix?

  • Sugar-phosphate backbone
  • Nitrogenous bases (Adenine, Thymine, Guanine, Cytosine)
  • Base pairs (A-T, G-C)
• What are the five nitrogenous bases that make up DNA?

  Adenine, Thymine, Guanine, Cytosine
• How are the nitrogenous bases paired in the DNA double helix?

  • Adenine (A) pairs with Thymine (T)
  • Guanine (G) pairs with Cytosine (C)
  • These base pairs are held together by hydrogen bonds
• If the sequence of one DNA strand is ATCG, what is the sequence of the complementary strand?

  TAGC
• How does each nucleotide link to the next?

  Via the phosphate group
• What is the chemical formula for the 5' phosphate group in DNA?

  O=P-O-CH2
• Why is the DNA structure twisted and compact?

  For efficient information storage
• What does the double helix structure of DNA resemble?

  A twisted ladder
• What role does deoxyribose play in DNA?

  It forms part of the DNA backbone
• How are the DNA bases paired in the double helix?

  • Adenine (A) pairs with Thymine (T)
  • Cytosine (C) pairs with Guanine (G)
• How are the base pairs in DNA arranged?

  • The base pairs are arranged in a double helix structure
  • Adenine (A) always pairs with Thymine (T)
  • Cytosine (C) always pairs with Guanine (G)
• Why are nitrogenous bases important in DNA?

  They store and carry genetic information
• What are the key features of the DNA double helix structure?

  • Two sugar-phosphate backbones
  • Base pairs (A-T, C-G) connect backbones
  • Twisted and compact for efficient storage
  • Each turn contains 10 base pairs
• How does complementary base pairing contribute to DNA structure?

  • Creates a stable double helix structure
  • Base pairs act like steps on a ladder
  • Ensures consistent DNA structure
  • Facilitates accurate replication
• What is the 5' phosphate group in DNA called?

  5' Phosphate
• How are the DNA base pairs connected in the double helix structure?

  • The base pairs are connected by hydrogen bonds:
  • A-T: 2 hydrogen bonds
  • C-G: 3 hydrogen bonds
  • The sugar-phosphate backbones run in opposite directions (antiparallel)
• What type of bonds hold the complementary base pairs together?

  Hydrogen bonds
• How does the specific pairing of bases ensure accurate DNA replication?

  It ensures each base bonds with its partner
• How many base pairs are in each turn of the DNA helix?

  10 base pairs
• What connects the sugar-phosphate backbones in DNA?

  Base pairs (A-T, C-G)
• What is the chemical formula for the 3' hydroxyl group in DNA?

  O-
• How does the chemical structure of the DNA backbone differ from the base pairs?

  The backbone is made of sugar-phosphate groups, while the base pairs are nitrogenous compounds
• If the sequence of one DNA strand is ATCGAT, what is the sequence of the complementary strand?


  TAGCTA
• Why do the base pairs in DNA always form specific pairs (A-T and C-G)?

  Due to the complementary hydrogen bonding patterns
• What is the role of the sugar-phosphate backbone in DNA?

  • Creates the outer structure of DNA chains
  • Links nucleotides together
• What are the chemical structures of the four DNA base pairs?

  • Thymine: 5' Phosphate, 5-Methyl Uracil ring
  • Adenine: 6-Amino Purine ring
  • Cytosine: 4-Amino Pyrimidine ring
  • Guanine: 2-Amino-6-Oxo Purine ring
• What three components make up a nucleotide?

  Deoxyribose sugar, phosphate group, nitrogenous base
• Why do the DNA bases pair in a specific way (A-T, C-G)?

  To maintain the stability and structure of the double helix
• How do nucleotides join to form DNA strands?

  Through their sugar-phosphate backbones