大象传媒

  • Key concepts in biology

    • Cell structure - Edexcel

      Light and electron microscopes allow us to see inside cells. Plant, animal and bacterial cells have smaller components each with a specific function.

    • Enzymes - Edexcel

      Enzymes are biological catalysts which speed up reactions. They are specific for their substrate. The lock and key hypothesis models this. Enzymes are denatured at extremes of temperature and pH.

    • Transport in cells - Edexcel

      Diffusion is the movement of particles from a high to lower concentration. Osmosis is the diffusion of water across a membrane. Active transport moves particles from low to higher concentration.

    • Sample exam questions - key concepts in biology - Edexcel

      Understanding how to approach exam questions helps to boost exam performance. Question types will include multiple choice, structured, mathematical and practical questions.

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