C1.1 Molecules-Enzymes and metabolism + D1.1-DNA Replication

• The synthesis of complex biological molecules from simpler molecules is called anabolism
• This image is of the enzyme catalase which breaks down hydrogen peroxide in living tissues releasing oxygen and water

  
• The type of biological molecule is catalase is a protein
• Enzymes involved in DNA replication molecular motion is necessary for a substrate molecule and an active site to come together. Also the substrate molecule is large, limiting its movement during interactions with enzymes.
• Shape of the active site will not be affected by immobilising an enzyme
• The Induced Fit model is considered more accurate because the Induced Fit model takes into account the three-dimensional structure of enzymes and substrates, including the precise bond angles and lengths that occur upon substrate binding.
• The graph below shows how temperature affects the rate of reaction caused by an enzyme such as catalase. At X the rate of reaction increases due to the increased kinetic energy of both the substrate and enzyme molecules

  
• The relationship between enzymes and the activation energy of a reaction is that the enzymes lower the activation energy required to break bonds within the substrate.
• These experiments showed that DNA replication was semi-conservative

  
• Meselon and Stahl grew E. Coli in a medium containing 15N for several generations. The part of the DNA molecule contains 15N is the nucleotide
• The role of the enzyme helicase in DNA replication is it 'unzips' the DNA, uses energy from the ATP (Adenosine triphosphate) and breaks the hydrogen bonds between complementary base pairs
• For a new strand of DNA to be made which of the following is required is the DNA polymerase, nucleotides and a template strand of DNA
• PCR used to amplify DNA
• Taq DNA polymerase used in PCR (Polymerase Chain Reaction) because it does not denature at 80oC
• Gel electrophoresis is used to separate fragments of DNA. The two factors that dictate how far the DNA molecules travel is their size and net negative charge
• The strategy can be employed to directly increase the reliability of DNA profiling in forensics by reducing the occurrence of false matches is by increasing the number of markers used
• What PCR (Polymerase Chain Reaction) and DNA replication have in common is that the use of primers, complementary base pairings and a template strand of DNA is needed