Nucleic Acid

• Nucleic acid


  macromolecule made of nucleotide monomers

  
• Two types of nucleic acids

  RNA (ribonucleic acid) and DNA (deoxyribonucleic acid)

  
• What does DNA do?

  stores and contains genetic information of an organism
• What is genetic information decoded into?

  amino acid sequences forming proteins
• How is DNA decoded?

  with the help of RNA molecules

  
• Nucleotide

  monomer of RNA and DNA polymers

  
• What are nucleotides made of?

  phosphate group, sugar with 5 carbon atoms, and a nitrogenous base
• What are the sugars in DNA and RNA?

  Ribose (RNA) and Deoxyribose (DNA)

  
• What is the difference between ribose and deoxyribose?

  ribose has a hydroxyl group bonded to its 2nd carbon atom, but deoxyribose only has a hydrogen atom bonded to its 2nd carbon atom
• What are the 2 types of nitrogenous bases?

  Pyrimidines and purines
• Pyrimidines


  cytosine, thymine, and uracil (single ring)

  
• Purines

  Adenine and Guanine (2 rings)

  
• What is a polymer of nucleotides called?

  a strand

  
• What is the covalent bond that holds nucleotides together?

  Phosphodiester bond

  
• What occurs during a phosphodiester bond?

  The phosphate group of one nucleotide bonds with the hydroxyl group of the next nucleotide in the strand, losing a water molecule
• DNA

  a double-strand twisted about each other to form a double helix

  
• What does DNA's backbone contain?

  Phosphate and a sugar
• How are nitrogenous base pairs held together?


  through hydrogen bonds

  
• What are the complementary base pairs?

  Adenine-Thymine, Cytosine-Guanine (A-T, G-C)

  
• Why is G-C pairing stronger than A-T pairing?

  because G-C contains 3 hydrogen bonds, which means there are more forces holding it together, while A-T only contains 2 hydrogen bonds

  
• Why do hydrogen bonds make bonds more stable?

  because the high electronegativity atom attracts the electrons from the hydrogen atom, therefore, making the bond stronger and more stable
• RNA


  only a single strand

  
• What is not present in RNA?

  Thymine, it is replaced with Uracil (U)
• What is the function of RNA?

  to decode DNA and carry messages outside the nucleus