B4 Biology OCR 21st Century (The Process of Life)

B4 Biology OCR 21st Century (The Process of Life)

1. Cells

   • Animal Cells
     • Mitochondria, Cytoplasm, Nuceus, Cell wall
   • Plant Cells
     • Cell Wall, Cell Membrane, Vacuole, Chloroplasts, Nucleus, Cytoplasm, Mitochondria

2. Enzymes

   • Protein Molecules
     • Speed up rate of chemical reactions in the body
     • Genes (DNA) codes for the type of enzyme that is produced in that cell
   • They have an optimum temperature at which they work best
     • If the temperature gets too high, the enzymes become denatured, meaning their structure changes so the substrate will no longer fit
   • The Lock and Key Model
     • Active Site
       • This is the part of the enzyme which the substrate fits into
         • Can be damaged by: 1) The temperature being too hot 2) The pH level
     • Only a certain shaped substrate will fit into the enzyme
       • A substrate fits in, the enzyme then brakes it down to make the products

3. Respiration

   • Aerobic
   • Anaerobic