2.1.2 Polynucleotide Chains

• Polynucleotide chains are long sequences of nucleotides linked by phosphate-sugar backbones.
• DNA and RNA are both types of polynucleotides.
• DNA consists of two polynucleotide chains forming a double helix.
• RNA typically consists of a single polynucleotide chain.
• Polynucleotide chains are formed by covalent bonds between the phosphate group of one nucleotide and the sugar of the next.
• A phosphate group is a negatively charged group attached to the 5' carbon of the sugar.
• Deoxyribose in DNA lacks an oxygen atom on the 2' carbon.
• Ribose in RNA has an oxygen atom on the 2' carbon.
• Uracil is a nitrogenous base found only in RNA.
• The phosphodiester bond links the phosphate group of one nucleotide to the 3' carbon of another nucleotide.
• The phosphodiester bond is formed through a condensation reaction where water is removed.
• Match the sugar in DNA and RNA with its property:

  Deoxyribose ↔️ Less stable due to less oxygen

  Ribose ↔️ More stable with additional oxygen
• What is the phosphodiester bond composed of in DNA and RNA?

  Phosphate group and sugar
• The phosphodiester bond links the phosphate group attached to the 5' carbon of one nucleotide to the 3' carbon of another nucleotide.
• The phosphodiester bond is formed through a condensation reaction where water is removed.
• Match the sugar type with its corresponding polynucleotide:

  Deoxyribose ↔️ DNA

  Ribose ↔️ RNA
• Which sugar is present in DNA?

  Deoxyribose
• The presence of oxygen in RNA makes it more stable compared to DNA.
• What is the typical structure of DNA?

  Double helix
• RNA is typically a single polynucleotide chain.
• Match the nitrogenous bases with their corresponding polynucleotide:

  A, G, C, T ↔️ DNA

  A, G, C, U ↔️ RNA
• What is the sugar in RNA called?

  Ribose
• Which nitrogenous base is unique to RNA?

  Uracil
• Directionality in DNA is crucial because enzymes can only add nucleotides to the3' end.
• How are the nucleotides in polynucleotide chains linked together?

  Covalent bonds
• DNA consists of two polynucleotide chains forming a double helix.
• What are the two types of polynucleotides mentioned in the study material?

  DNA and RNA
• DNA consists of two polynucleotide chains forming a double helix
• RNA typically consists of a single polynucleotide chain.
• What type of bonds link nucleotides in a polynucleotide chain?

  Covalent bonds
• The sugar in DNA is called deoxyribose
• RNA contains the nitrogenous base uracil (U) instead of thymine (T).
• What are the two main components of a polynucleotide chain's backbone?

  Phosphate and sugar
• Match the polynucleotide chain with its structure:

  DNA ↔️ Double helix

  RNA ↔️ Single strand
• A nucleotide consists of a phosphate group, a pentose sugar, and a nitrogenous base
• To which carbon of the pentose sugar is the phosphate group attached?

  5'
• Deoxyribose lacks an oxygen atom on the 2' carbon.
• Match the pentose sugar with its polynucleotide:

  Deoxyribose ↔️ DNA

  Ribose ↔️ RNA
• What is the name of the bond that links nucleotides in a polynucleotide chain?

  Phosphodiester bond
• The phosphodiester bond is formed through a condensation reaction where a molecule of water is removed.