nucleotides

• There are two types of nucleic acid:

  • DNA stands for Deoxyribonucleic acid

  • RNA stands for ribonucleic acid
• Nucleic acids are made up of carbon, hydrogen, oxygen, nitrogen and phosphorus. They are polymers of nucleotides (the monomer).

   Nucleotides are made up of a pentose sugar, a phosphate group and a nitrogenous base

  
• phosphate group - PO42- : An acidic inorganic molecule which is negatively charged.

  pentose sugar - A pentose monosaccharide containing 5 carbon atoms.

  nitrogenous base - Complex molecules containing carbon and nitrogen. In DNA there are 4 bases.

  
• • The pentose sugar in DNA is deoxyribose
  • The pentose sugar in RNA is ribose.
  • Deoxyribose has one less oxygen atom than ribose

  
• In DNA there are four different nitrogenous bases

  1. adenine
  2. cytosine
  3. guanine
  4. thymine

  In RNA one of the nitrogenous bases is different

  1. adenine
  2. cytosine
  3. guanine
  4. uracil
• Nucleotides are joined by condensation reactions to form polynucleotides.

  Phosphodiester bonds are formed between the phosphate group of the fifth carbon of the pentose sugar and the hydroxyl group of the third carbon of an adjacent nucleotide.

  
• What is the monomer of DNA?

  nucleotide
• What does DNA stand for?

  deoxyribonucleic acid
• Complementary base pairs are joined by what bond?

  hydrogen
• Give 3 ways in which DNA is different to RNA

  1. Pentose sugar in DNA 6’ Deoxyribose, pentose sugar in RNA is ribose.
  2. One less oxygen in DNA pentose sugar.
  3. Uracil instead of Thymine in RNA
• There are more nucleotides than just RNA and DNA.

  ATP – Adenosine Tri Phosphate

  ADP – Adenosine Di Phosphate

  These are phosphorylated nucleotides.

  ATP has a nitrogenous base, pentose sugar and 3 phosphate groups. The base is always adenine and the sugar is ribose.

  ADP has a nitrogenous base, pentose sugar and 2 inorganic phosphate groups.

  
• •The base of ATP and ADP is adenine

  •The sugar in ATP and ADP is ribose

  •ATP has 3 phosphate groups and ADP has 2.
• ATP is able to supply energy to the body for processes such as movement, synthesis and transport.

  Properties of ATP for this:

  •Small

  •Water soluble

  •Releases energy in small quantities

  •Easily regenerated
• ATP is hydrolysed into ADP and a phosphate ion, releasing energy