DNA and RNA

• What does DNA stand for?

  deoxyribonucleic acid
• What is DNA used to do?

  store genetic information - all the instructions an organism needs to grow and develop from a fertilised egg to a fully grown adult
• What does RNA stand for?

  ribonucleic acid
• what is one of the main functions of RNA?

  To transfer genetic information from the DNA to the ribosomes. Ribosomes read the RNA to make polypeptides during translation
• what are ribosomes made from?

  RNA and proteins
• what is a nucleotide a type of?

  biological molrculre
• what are nucleotides made from?

  A pentose sugar

  a nitrogenous organic base

  A phosphate group
• what does organic means?


  it contains carbon
• what is a pentose sugar?

  a sugar with 5 carbon atoms
• what are the components of a DNA nucleotide?

  deoxyribose sugar

  a phosphate group

  one of the nitrogen containing organic bases (adenine, cytosine, guanine or THYMINE)
• what are the components of an RNA nucleotide?

  ribose sugar

  a phosphate group

  one of the nitrogen containing organic bases (adenine, cytosine, guanine or URACIL)
• How do nucleotides join together?

  By phosphodiester bonds formed in condensation reactions.

  The result is a DINUCLEOTIDE, which join to form polynucleotides.

  The bond forms between the deoxyribose sugar of one nucleotide and the phosphate group of another
• Where does the bond between each nucleotide form?

  the bond forms between the deoxyribose sugar of one nucleotide and the phosphate group of another
• What is a DNA molecule?

  a double helix composed of two polynucleotides joined together by a hydrogen bond between complementary based
• What is a RNA moleucle like?

  RNA is a relatively short polynucleotide chain
• How do base pairing nitrogen containing organic bases occur?

  Adenine always with thymine

  guanine always with cytosine
• Why is DNA a stable molecule?

  • The phosphodiester backbone protects the more chemically reactive nitrogen containing organic bases insidethe double helix
  • Hydrogen bonds form bridges between the phosphodiester uprights. Because there are 3 hydrogen bonds between G&C, rather than 2 for A&T, a higher proportion of C-G pairings makes DNA more stable
• what is the definition of DNA?

  an information storing molecule made up of deoxyribonucleotide monomers joined up by phosphodiester bonds to form a double helix
• what is the definition of DNA helicase?

  an enzyme that breaks the hydrogen bonds between the 2 DNA strands in the DNA molecule that is going to be replicated
• what is the definition of DNA polymerase?

  an enzyme that catalyses the condensation reactions between the new nucleotides in the synthesis of the new DNA strand
• what is the definition of RNA?

  a relatively short molecule made of ribonucleotide monomers joined by phosphodiester bonds