3.1.6. ATP

• Adenosine Triphosphate is a nucleotide derivative


  A molecule of:

  • Ribose
  • Adenine
  • 3 phosphate groups
• Energy is released when ATP is hydrolysed to ADP and an inorganic phosphate molecule; catalysed by the enzyme ATP hydrolase
• Inorganic phosphate can be used to phosphorylate other compounds

  • Makes them more reactive
  • Released during hydrolysis of ATP
• ATP synthase catalyses the condensation of ADP and inorganic phosphate to form ATP

  • During photosynthesis or respiration
• ATP properties

  Immediate source of energy

  • Can be broken down in a single step; releases a manageable quantity of energy

  Isn’t stored in large quantities

  • Reformed from ADP in seconds; saves space

  Used in a variety of ways

  • Metabolic processes, movement, active transport, secretion and activation of molecules
• ATP resynthesis

  1. By ATP synthase
  2. Using ADP and Pi
  3. During respiration/photosynthesis
• Use of ATP hydrolysis

  1. Phosphorylate other compounds to make them more reactive
  2. Provide energy for other reactions.
• Induced fit model

  1. Active site not complementary to substrate
  2. Substrate binds to enzyme, causing the shape of the active site to undergo conformational change, forming an enzyme-substrate complex.
  3. Stresses bond in substrate resulting in reaction.
• How can two different enzymes catalyse the same substrate?

  Different amino acid sequences of protein

  • Each enzyme is complementary to a different part of the protein.
• Inhibitors

  Block active site of enzymes.
• Capsid

  Viral protein layer
• Capsule

  Bacterial protective layer
• Viral replication

  1. Reverse transcriptase converts RNA into DNA
  2. DNA is incorporated it into T-helper cell DNA
  3. DNA is transcribed into viral mRNA
  4. mRNA is translated into new viral proteins
• Viral Replication from beginning

  1. Virus attachment proteins attach to receptors on T-helper cells
  2. RNA enters cell
  3. Reverse transcriptase converts RNA to DNA
  4. Viral proteins produced
  5. Virus assembled and released from cell.
• Antigenic variability‘s effect on species

  Mutation in viral RNA alters tertiary structure of viral attachment protein.

  • Allows virus to bind to receptors of other species.
• Genome of viruses and how they aid in vaccine development

  1. Scientists can identify proteins/proteome
  2. Can identify potential antigens