types of cells

• bacterial cells contain

  • cytoplasm- where most chemical reactions take place
  • plasmids- small loops of dna are stored
  • cell wall and membrane- provides structure
  • flagella- whip like structures used for movement
• Components of plant cells

  • Nucleus
  • Ribosomes
  • Chloroplast
  • Mitochondria
  • Cytoplasm
  • Cell membrane
  • Cell wall
  • Permanent vacuole
• Nucleus

  Contains genetic information including DNA which controls the cell's activity
• Ribosomes

  Organelle where protein synthesis occurs
• Chloroplast

  Contains chlorophyll (a green pigment which absorbs light energy) needed for photosynthesis
• Mitochondria

  Contains enzymes for aerobic respiration where most energy is released
• Cytoplasm

  Jelly-like material that contains dissolved nutrients, salts and is where most chemical reactions take place
• Cell membrane

  Permeable structure that controls the movement in and out of the cell
• Cell wall

  Made from cellulose and increases the strength and supports the plant
• Permanent vacuole

  Filled with cell sap to help the cell turgid
• components of an animal cell

  • nucleus
  • cytoplasm
  • ribosomes
  • cell membrane
  • mitochondria
• • Phloem cells
  • The cell walls between the cells break down to form special sieve plates that allow water carrying dissolved food to move freely up and down the tubes to where it is needed, and phloem cells lose a lot of their internal structures but they are supported by companion cells that help to keep them alive and the mitochondria of the companion cells transfer the energy needed to move dissolved food up and down the plant in phloem
• xylem cells

  • they have a special chemical called ligin that builds up in spirals in the cell walls, the cells die and form long hollow tubes that allow water and mineral ions to move easily through them from one end of the plant to the other, and the spirals and rings of ligin in the xylem cells make them very strong and help them withstand the pressure of water moving up the plant and also helps support the plant
• photosynthetic cells

  they contain specialised green structures called chlorplasts containing chlorophyll that trap the light needed for photosynthesis, they are usually positioned in continuous layers in the leaves and outer layers of the stem of a plant so they absorb as much light as possible, and they have a large permanent vacuole that helps keep the cell rigid as a result of osmosis
• root hair cells

  they greatly increase the surface area available for water to move into the cell, they have a large permanent vacuole that speeds up the movement of water by osmosis from the soil across the root hair cell, and they have many mitochondrias that transfer the energy needed for the active transport of mineral ions into the root hair cell
• sperm cell

  they have a long tail that whips from side to side to help move the sperm through water or the female reproductive system, the middle section is full of mitochondria which transfers the energy needed for the tail to work, the acrosome stores digestive enzymes for breaking down the outer layers of the egg, and a large nucleus contains the genetic information to be passed on
• muscle cells

  • they are specialised cells that contract and relax
  • striated muscle cells have three main adaptations; they contain special proteins that slide over each other making fibres contract, they contain many mitochondria to trasnfer the energy needed for the chemical reactions that take place as the cells contract and relax, and they can store glycogen (a chemical that can be broken down and used in cellular respiration by the mitochondira to transfer the energy needed for the fibres to contract)
• nerve cells

  • they are specialised to carry electrical impulses around the body of an animal
  • they have several adaptations including lots of dendrites to make connections to other nerve cells, an axon that carries the nerve impulse from one place to another, and a nerve ending or synpases that are adapted to pass the impulse to another cell or between a nerve cell and a muslce in the body using special transmitter chemicals
  • they contain lots of mitochondria to provide enery needed to make the transmitter chemicals