Key concepts

• Active transport-used when going against a concentration gradient or when molecules are too big to diffuse.

  it moves substances across a cells semi permeable membrane.

  It needs energy
• A prokaryote is a simple cell without a nucleus and other membrane bound organelle.

  An example is bacteria
• A eukaryote is a complex cell which contains a nucleus and other membrane bound organelle.

  An example is animal.
• Diffusion is when particles move from a high concentration to a low concentration.

  It moves substances across a cells semi permeable membrane.

  It is faster when heated because the particles have more kinetic energy.
• Osmosis is the diffusion of water molecules
• An enzyme is a protein which acts as a natural catalyst to speed up chemical reactions.

  Examples are respiration, photosynthesis, digestion.
• If a temperature is too hot, proteins begin to fold up which can change the shape of the active Sights Which means substrate will not fit in. This means the enzyme has been denatured.

  This is the same for ph and substrate concentration.
• A sperm cell is the male gamete.

  
• An egg cell is the female gamete.