Prokaryotic cells

• how are prokaryotic cells different to eukaryotic cells?

  they are smaller and simpler than eukaryotic cells
• give an example of a prokaryotic cell?

  Bacteria
• what is the plasma membrane mainly made of ?

  lipids and proteins
• what's the function of the plasma membrane?

  control the movement of substances into and out of the cell
• what is the function of the cell wall?

  supports the cell & prevents it from changing shape
• what is the cell wall made up of?

  a polymer called murein
• what is murein?

  a glycoprotein
• what is a glycoprotein?

  a protein with a carbohydrate attached
• what do some prokaryotes such as bacteria have?

  a capsule made up of secreted slime

  • helps to protect bacteria from attack by cells of the immune system
• what are plasmids?

  small loops of DNA that are NOT part of the main circular DNA molecule
• what do plasmids contain?

  genes for antibiotic resistance
• can plasmids be passed between prokaryotes?

  yes
• are plasmids always present in prokaryotic cells?

  no

  -and some prokaryotic cells have several plasmids
• does a prokaroytic cell have a nucleus?

  no
• what do prokaryotic cells have instead of a nucleus?

  the DNA floats free in the cytoplasm
• describe DNA in a prokaryotic cell?

  -floats free in the cytoplasm

  -circular DNA, present as one long coiled-up strand

  -not attached to any histone proteins
• what is the plural of flagellum?

  plural= flagella
• what is the flagellum?

  a long, hair-like structure that rotates to make the prokaryotic cell move
• not all prokaryotes have a flagellum. some have MORE THAN ONE!
• what does the cytoplasm of a prokaryotic cell NOT contsin?

  • has NO membrane-bound organelles
  • it has ribosomes which are smaller than those in a eukaryotic cell