Structure of DNA and RNA

• What is the structure of a nucleotide?


  It consists of a phosphate molecule, pentose sugar, and a nitrogen-containing organic base.
• Why is a pentose sugar known as that?

  It consists of five carbon atoms.
• What are the 5 nitrogen-containing organic bases?


  Adenine, guanine, cytosine, thymine, and uracil
• What does RNA mean?


  Ribonucleic acid.
• What does DNA mean?


  Deoxyribonucleic acid.
• What does DNA carry?

  Genetic information.
• What is DNA made up of?

  Nucleotides.
• How are nucleotides formed?

  By a condensation reaction.
• What is a mononucleotide?


  A singular nucleotide.
• What is a dinucleotide?

  Two nucleotides joined together.
• What is a polynucleotide?


  A long chain of nucleotides joined together.
• What is the bond formed between nucleotides called?

  A phosphodiester bond.
• How do nucleotides join together?


  A condensation reaction between the pentose sugar on one nucleotide and the phosphate on the other.
• What is RNA?


  A short polymer of nucleotides (polynucleotide).
• What is the pentose sugar in RNA?


  Ribose.
• What are the organic bases in RNA?


  Adenine, guanine, cytosine, and uracil.
• What are the 3 functions of RNA?


  Transfers genetic information from DNA to ribosomes, it makes up some of a ribosome, and is involved in protein synthesis.
• What is the pentose sugar in DNA?


  Deoxyribose.
• What are the organic bases in DNA?

  Adenine, guanine, cytosine, and thymine.
• What is DNA made of?

  Two long polynucleotides.
• What is the shape of DNA?

  A double helix.
• How are the 2 polynucleotides joined in DNA?

  By hydrogen bonds between the bases.
• What bases is adenine complementary to?


  Thymine and uracil.
• What base is guanine complementary to?

  Cytosine.
• What is always equal in DNA?

  The quantities of adenine to thymine, and guanine to cytosine.
• What arrangement is DNA said to be like?


  Ladder-like.
• How is DNA like a ladder?


  Deoxyribose and phosphate molecules are the uprights, and the organic bases are the rungs
• How is DNA a stable molecule?


  Due to the phosphodiester backbone that protects the more chemically reactive organic bases, and strong hydrogen bonds link base pairs.
• How many hydrogen bonds are there between adenine and thymine?

  2
• How many hydrogen bonds are there between guanine and cytosine?

  3
• What does it mean if there is a high proportion of G-C base pairs in a DNA molecule and why?

  The DNA molecule will be more stable as G-C base pairs have 3 strong hydrogen bonds.
• What does the function of DNA depend on?

  Its sequence of base pairs.
• What is DNA?


  A hereditary material responsible for passing genetic information from generation to generation.
• How does genetic diversity occur between DNA?

  Due to the infinite variety of sequences of bases along DNA.
• What adaptations does DNA have?


  It's very stable, strands can separate as they are joined by hydrogen bonds, genetic information is protected by backbond, and it can replicate due to base pairing.
• What are rare in DNA and why?

  Mutations, as the molecule is stable and easily repaired.