B1

• DNA


  Two strands wrapped around each other in a double helix
• Structure of DNA

  1. Nucleotides

  2. Complementary base pairing

  3. Gene coding for a protein
• Nucleotide


  Monomer unit of DNA, made up of a phosphate, sugar, and base
• Bases in DNA


  • Adenine
  • Thymine
  • Cytosine
  • Guanine
• DNA


  • Polymer made up of many nucleotides
  • Sugar phosphate backbone
  • Bases hold the two strands together through complementary base pairing
• Complementary bases


  A pairs with T, C pairs with G
• Determining complementary DNA strand


  Look at sequence of one strand and determine complementary bases for other strand
• Genetic code


  Sequence of DNA bases
• Gene


  Particular sequence of bases that codes for a protein
• Protein formation from DNA


  1. DNA sequence read as triplets

  2. Triplets code for specific amino acids

  3. Amino acids combine in order to form protein

  4. Protein folds into unique shape
• Proteins


  • Act as enzymes, hormones, and structural components
  • Each type has a unique shape based on its amino acid sequence
• How temperature and pH affect the functioning of enzymes and the rate of enzyme controlled reactions

  1. Temperature increases

  2. Rate of reaction increases

  3. Temperature reaches 37 degrees

  4. Rate of reaction starts to drop rapidly

  5. Enzyme becomes denatured at around 45 degrees

  6. Optimal temperature is 37 degrees
• Denatured


  Enzyme's shape changes so it can no longer bind to the substrate and catalyze the reaction
• Optimal temperature


  Temperature at which the rate of reaction is highest
• How pH affects enzymes

  1. pH gets too high or too low

  2. Bonds holding the enzyme together start to break

  3. Active site changes shape

  4. Substrate can no longer fit

  5. Enzyme becomes denatured
• Optimal pH


  pH at which the enzyme works best
• Most enzymes in our body work best at neutral pHs of around 7
• Enzymes that work in the stomach have an optimal pH of around 2 because they need to function in the stomach's acidic environment