Test 4

• Cell Wall


  A rigid structure around the outside of the cell that gives strength to the cell. A prokaryotic cell wall is different from a plant cell wall because it is NOT made from cellulose.
• Cell membrane


  Controls the movement of substances into and out of the cell. Some substances can move freely through the membrane and others cannot, so we say the membrane is semi-permeable (or partially permeable).
• Cytoplasm


  This is where most of the chemical reactions in a cell take place. There are enzymes in the cytoplasm to control (catalyse) the chemical reactions.
• Ribosomes


  This is where proteins synthesis takes place (protein synthesis means making proteins).
• DNA loop


  The genetic material of the cell. It is NOT in a nucleus, it floats freely in the cytoplasm and it is one piece of circular DNA.
• Plasmids


  Small rings of DNA. This is extra genetic material. There may different numbers of plasmids in different prokaryotic cells.
• Permanent vacuole


  Contains cell sap which is a fluid made of water with sugars and salts dissolved in it
• Chloroplasts


  • Contains a green chemical (pigment) called chlorophyll that absorbs light
  • The site of photosynthesis (chemical reaction that makes sugar)