Biology

• Enzymes are protein molecules that act as biological catalysts, accelerating the rate of chemical reactions by lowering the activation energy
• The activation energy (EA) is the minimum amount of energy required for the reactants to be converted to products
• An enzyme is made up of chains of amino acids linked together by peptide bonds
• All cells contain enzymes depending on the type of the living cell engaged in tremendous biochemical activity called metabolism
• Metabolism is the process of chemical and physical changes, including the breakdown (catabolism) and synthesis (anabolism) of molecules
• The metabolic processes in cells require enzymes to catalyze many biochemical reaction types at rates fast enough to sustain life
• Enzymes act by converting substrates (starting molecules) into products and remain unchanged themselves
• Enzymes accelerate reaction rates and distort the shape of substrates
• Enzymes are denatured by high heat above 40°C
• Enzymes neither appear in the nature as products formed nor undergo any chemical changes by the reaction catalyzed
• Denaturation of enzymes involves breaking the intramolecular and intermolecular covalent bonds
• A physical ppt on enzymes includes denaturation, solubility, catalysis, precipitation, molecular weight, and activation energy
• Solubility is the property of enzymes that allow them to be dissolved in water, salt solutions, diluted glycerol, and alcohol, causing denaturation
• Enzymes have little or no dialysis across semipermeable membranes due to their large size and high molecular weights
• The biocatalyst property of enzymes is their activity where a very small quantity of enzyme is enough to convert a large quantity of substrate and remain unchanged after the reaction
• Enzyme precipitation is the separation of enzymes for analysis using an aqueous or ethanol solvent
• Enzymes are large protein biomolecules that hold polypeptide chains of various amino acid sequences, having a high molecular weight
• Enzyme activity is the general catalytic property of enzymes
• Enzymes


  • Cactase
  • Lipase
  • Carbohydrase
  • Pratense
• Cactase


  Breaks down lactose which is a milk
• Lipase


  Breaks down fat into fatty acids and glycerol
• Carbohydrase


  Breaks down carbohydrates into sugars
• Pratense


  Breaks down proteins into amino acids
• Enzymes


  Lower the activation energy required for a reaction to occur
• Lower activation energy


  The faster the reaction happens without an enzyme
• Activation energy is the energy required for a reaction to occur
• Without an enzyme, a higher activation energy is required for a reaction to occur
• With an enzyme, a lower activation energy is required for a reaction to occur
• The lower the activation energy, the faster the reaction happens with an enzyme
• Protein


  A polymer of amino acids joined in 3 dimensional arrangements of atoms in amino acids chain molecules
• Types of protein structures

  • Primary structure
  • Secondary
  • Tertiary
  • Quaternary
• Primary structure of proteins

  The sequence of amino acids based on the side chain substitutes that differ by the chemical, physical and structural properties
• Peptide bonds


  The bonds created during the biosynthesis process that link amino acids together to form a polypeptide chain
• Proteins with fewer than 50 amino acids are peptides and proteins with longer sequences of amino acids are polypeptides
• Human require some amino acids out of

  20
• Secondary structure of proteins

  A folded structure formed within a polypeptide due to interactions between atoms of the backbone based on hydrogen bonding and containing α-helix and ß-sheet types of strands
• Secondary structure of proteins

  • Contains α-helix and ß-sheet types of strands
• α-helix


  • A right-handed coiled strand with side-chain substituents of amino acid groups extending to the outside and forming hydrogen bonds with oxygen (C=O) in the strand with the hydrogen of each (N-H) group of four amino acids to make the structure stable
• Formation of α-helix


  The polypeptide chain twists into a right-handed screw with the NH group of each amino acid residue hydrogen-bonded to the CO of the adjacent turn of the helix
• ß-sheet


  • Hydrogen bonding between the inter-strands and intra-strands in which the sheet conformation of the ß-sheet consists of pairs of strands lying side-by-side