1. Bacteria

3. Cell wall Made of a peptidoglycan called murein. This is laid down as a network of polysaccharide fibres. A strong layer that prevents the cell from bursting and excludes certain substances Cell surface membrane Normal fluid mosaic structure Controls the passage of substances in and out of the cell. Can be folded inwards to give additional surface area to house molecules involved in respiration reactions Genetic materialA circular strand of DNATo control the cell

4. Ribosomes These are a smaller type (70S) than those found in eukaryotic cells Protein synthesis Capsule Protects against chemicals and desiccation. Also protects the bacterium from attack by phagocytic cells such as our white blood cells. flagellumMade of a single, long fibre up to 20 µm long. These may be present singly, at one or both ends or even all over the cell.

5. pili Fine threadlike structures attached to the capsule or cell wall. Up to 1 µm long For attachment to surfaces plasmidsSmall loops of DNA Carry some additional genes. This is where genes giving antibiotic resistance would be found. Used in genetic engineering for transferring foreign genes into bacterial cells Oil droplets/glycogen granules As a food store

7. Mycobacterium tuberculosis is a Gram-positive, rod-shaped bacterium and the cause of tuberculosis in humans

8. Tuberculosis is primarily an airborne disease; it is spread from person to person by droplet infection when an active TB sufferer coughs and sneezes

9. The most common salmonellosis is enterocolitis, caused principally by Salmonella enteriditis and Salmonella typhimurium. Food poisoning caused by S. enteriditis and S. typhimurium occurs when these bacteria are present in sufficient numbers in consumed food. A bacterial load of  100,000 per gram of food is sufficiently high for many of the bacteria to survive the digestion process, and to continue multiplying within the gut.