Cell Structure

• The two types of eukaryotic cell are animal and plant.
• Bacteria are prokaryotic cells.
• DNA is found in the nucleus in eukaryotic cells.
• The cell membrane controls movement of substances in and out of the cell.
• The mitochondria is the site of respiration to transfer energy for the cell.
• Chloroplasts contain chlorophyll to absorb light energy for photosynthesis.
• Ribosomes enable production of proteins (protein synthesis).
• The cell wall strengthens and supports the cell.
• The structure of the main genetic material in a prokaryotic cell is a single loop of DNA.
• Differences between electron and light microscopes:

  Electron microscopes use beams of electrons instead of light.

  Electron microscopes cannot view living samples.

  Electron microscopes are much more expensive.

  Electron microscopes have much higher magnification and resolution.
• Red blood cells carry oxygen around the body.
• Red blood cell adaptions:

  No nucleus.

  Contains a red pigment call haemoglobin.

  Has a bi-concave disc shape.
• Nerve cells carry electrical impulses around the body.
• Nerve cell adaptations:

  Branched endings.

  Myelin sheath insulates the axon.
• Sperm cells fertilise ova (eggs).
• Sperm cell adaptations:

  A tail.

  Contains lots of mitochondria.
• Palisade cells carry out photosynthesis in a leaf.
• Palisade cell adaptations:

  Lots of chloroplasts.

  Located at the top of a leaf.
• Root hair cells absorb minerals and water from the soil.
• Root hair cell adaptations:

  Long projection.

  Lots of mitochondria.